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6-K

National Steel Co (SID)

6-K 2026-05-29 For: 2026-03-31
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Added on May 30, 2026

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer Pursuant to Rule 13a-16 or 15d-16 of the

Securities Exchange Act of 1934

For the month of May, 2026 Commission File Number 1-14732

COMPANHIA SIDERÚRGICA NACIONAL

(Exact name of registrant as specified in its charter)

National Steel Company

(Translation of Registrant's name into English)

Av. Brigadeiro Faria Lima 3400, 20º andarSão Paulo, SP, Brazil04538-132

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.  Form 20-F ___X___ Form 40-F _______

Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934. Yes _______ No ___X____
Companhia Siderúrgica Nacional S.A.
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BALANCE SHEET
(In thousands of Reais)
Consolidated Parent Company Consolidated Parent Company
Notes 03/31/2026 12/31/2025 03/31/2026 12/31/2025 Notes 03/31/2026 12/31/2025 03/31/2026 12/31/2025
ASSET LIABILITIES AND SHAREHOLDERS' EQUITY
Current Current
Cash and cash equivalents 4 12,822,834 14,421,022 1,785,070 3,529,453 Borrowings and financing 13 9,075,555 10,428,559 4,957,784 6,190,764
Financial investments 5 616,711 642,715 427,506 380,974 Payroll and related taxes 579,876 549,940 189,202 183,695
Trade receivables 6 2,897,876 2,397,033 2,101,001 1,702,245 Trade payables 16 6,531,907 7,162,929 4,321,780 3,941,596
Inventory 7 10,170,174 10,455,500 6,283,569 6,205,488 Tax payables 771,441 736,075 161,476 93,023
Recoverable taxes 8 1,666,038 1,376,434 564,702 511,925 Labor and civil provisions 20 56,009 61,455 35,235 40,225
Other current assets 9 1,218,235 1,037,925 1,215,900 1,867,765 Dividends and interest on equity payable 18 1,140,000 358,039 6,047 6,059
Total current assets 29,391,868 30,330,629 12,377,748 14,197,850 Contracts liabilities 17 4,530,955 4,347,937 563,043 481,905
Trade payables – forfaiting 16.a 2,410,807 2,905,018 1,606,945 1,924,285
Non-Current Other payables 18 1,385,393 1,524,447 1,039,713 1,038,720
Long-term realizable asset Total current liabilities 26,481,943 28,074,399 12,881,225 13,900,272
Financial investments 5 25,867 25,257
Deferred taxes assets 19.b 7,104,779 7,100,375 4,939,182 4,885,921 Non-Current
Inventory 7 2,136,768 2,073,526 Borrowings and financing 13 41,359,574 42,495,988 20,349,833 21,285,656
Recoverable taxes 8 3,782,617 3,976,900 2,722,201 2,740,860 Deferred taxes assets 19.b 571,484 589,451
Other non-current assets 9 3,416,247 3,851,362 4,404,637 4,756,511 Provision for tax, social security, labor, civil and environmental risks 20 867,359 812,721 307,966 300,951
16,466,278 17,027,420 12,066,020 12,383,292 Employee benefits 423,086 402,415 389,689 379,160
Provisions for environmental liabilities and decommissioning 21 1,217,461 1,187,609 110,674 111,789
Investments 10 8,181,651 8,292,026 24,777,044 24,855,198 Provision for investment losses 10 11,175,357 11,446,531
Property, plant and equipment 11 34,133,001 33,919,169 10,818,058 10,729,570 Contracts liabilities 17 9,787,198 9,026,766 648,970 738,099
Intangible assets 12 10,955,538 11,006,125 75,150 65,956 Other payables 18 2,525,948 2,249,670 1,400,545 1,193,349
Total non-current assets 69,736,468 70,244,740 47,736,272 48,034,016 Total non-current liabilities 56,752,110 56,764,620 34,383,034 35,455,535
Shareholders’ equity 23
Paid-up capital 23.a 10,240,000 10,240,000 10,240,000 10,240,000
Capital reserves 1,758,328 2,056,970 1,758,328 2,056,970
Legal reserves - -
Earnings reserves - -
Net income/(loss) (818,520) (202,989) (818,520) (202,989)
Other comprehensive income 1,669,953 782,078 1,669,953 782,078
Total shareholders' equity of controlling shareholders 12,849,761 12,876,059 12,849,761 12,876,059
Earnings attributable to the non-controlling interests 3,044,522 2,860,291
Total shareholders' equity 15,894,283 15,736,350 12,849,761 12,876,059
TOTAL ASSETS 99,128,336 100,575,369 60,114,020 62,231,866 TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY 99,128,336 100,575,369 60,114,020 62,231,866
The Accompanying notes are an integral part of these consolidation financial statement
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Companhia Siderúrgica Nacional S.A.
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Statements of Income
(In thousands of Reais)
Consolidated Parent Company
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Notes 03/31/2026 03/31/2025 03/31/2026 03/31/2025
Net Revenue 25 10,603,772 10,907,629 3,843,218 4,490,324
Cost from sale of goods and services rendered 26 (8,081,068) (8,375,386) (3,696,417) (4,203,998)
Gross profit 2,522,704 2,532,243 146,801 286,326
Operating (expenses)/income (2,228,360) (1,644,606) (687,136) (474,321)
Selling expenses 26 (1,096,940) (1,060,232) (173,136) (205,282)
General and administrative expenses 26 (240,963) (217,398) (89,101) (88,214)
Equity in results of affiliated companies 10 23,777 78,434 283,911 89,377
Other operating (expenses)/income,<br> net 27 (914,234) (445,410) (708,810) (270,202)
Other operating income 6,431 65,764 37,220 45,243
Other operating expenses (920,665) (511,174) (746,030) (315,445)
Income before financial income (expenses) 294,344 887,637 (540,335) (187,995)
Financial income (expenses), net 28 (1,306,852) (1,850,347) (612,134) (784,539)
Financial income 327,574 555,057 219,676 248,352
Financial expenses (1,543,035) (1,700,408) (676,729) (651,894)
Other financial items, net (91,391) (704,996) (155,081) (380,997)
Income before income taxes (1,012,508) (962,710) (1,152,469) (972,534)
Income tax and social contribution 19 457,485 231,130 536,938 353,388
Net income for the exercise (555,023) (731,580) (615,531) (619,146)
Attributable to:
Earnings attributable to the controlling interests (615,531) (619,146) (615,531) (619,146)
Earnings attributable to the non-controlling interests 60,508 (112,434)
Loss basic and diluted per share (in R$) 23.g (0.41854) (0.46689)
The Accompanying notes are an integral part of these consolidation financial statement
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Companhia Siderúrgica Nacional S.A.
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Statements of Cash Flows
(In thousands of Reais)
Consolidated Parent Company
Notes 03/31/2026 03/31/2025 03/31/2026 03/31/2025
Net cash from operating activities (776,501) (1,153,595) (214,844) (295,740)
Cash flow from operating activities 930,782 513,588 (93,419) 250,390
Earnings  attributable to the controlling interests (615,531) (619,146) (615,531) (619,146)
Earnings attributable to the non-controlling interests 60,508 (112,434)
Adjustments to reconcile the result:
Financial charges in borrowing and financing raised 28 928,280 1,021,836 407,805 449,426
Financial charges in borrowing and financing granted (55,241) (95,345) (93,842) (76,950)
Charges on lease liabilities 16 31,084 25,139 829 884
Equity in results of affiliated companies 10 (23,777) (78,434) (283,911) (89,377)
Deferred taxes assets 20.b (572,776) (434,902) (536,938) (353,388)
Provision for tax, social security, labor, civil and environmental risks 62,401 15,428 2,026 (1,203)
Exchange, Monetary and Cash Flow Hedge (62,632) (172,559) 674,007 648,834
Write-off of property, plant and equipment right to use and Intangible assets 11, 12, 13 and 16 2,024 (12,886) 39,223 (14,177)
Provision for environmental liabilities and decommissioning of assets 29,851 44,720 (1,115) (2,005)
Updated shares – Fair value through profit or loss 28 (46,230) (50,772) (46,698) (50,772)
Depreciation, amortization and depletion 10,11 e 12 1,155,156 999,188 331,852 354,424
Accrued/(reversal) for consumption and services (13,019) (34,048) 873 (820)
Others 50,684 17,803 28,001 4,660
Changes in assets and liabilities (1,707,283) (1,667,183) (121,425) (546,130)
Trade receivables - third parties (447,284) 547,478 (194,829) 207,299
Trade receivables - related party (45) (2,768) (140,786) (177,145)
Inventory 104,569 (3,243) (78,081) 124,025
Dividends and receivables - related parties 1,317 744,407 (107,805)
Recoverable taxes (95,320) (76,918) (34,118) 17,092
Judicial deposits (1,648) 10,791 1,154 891
Trade payables (554,587) (393,885) 379,840 (219,682)
Trade payables – Forfaiting and Drawee risk (490,496) 147,404 (317,339) 299,606
Tax payables 69,810 (98,078) 73,187 (48,821)
Payables to related parties (65,086) (23,179) (25,841) 2,878
Costumers advances under mineral and energy contracts 867,195 (737,841) (89,129) (239,355)
Interest paid 14.a (878,933) (962,355) (352,651) (350,492)
Receipts/(Payments) from hedging operations, cash flow and derivatives (212,779) (72,572) (31,098) (16,908)
Other liabilities (2,679) (3,334) (56,141) (37,713)
Net cash investment activities (626,080) (1,182,781) 9,095 (1,108,438)
Investments / AFAC / Acquisitions of Shares (95,365) (23,600) (81,636) (36,600)
Purchase of property, plant and equipment, intangible assets and  investment  property 10,11 and 12 (1,125,593) (1,126,705) (405,788) (541,396)
Intercompany loans granted (6,836) (20,212) (540,998)
Intercompany loans received 530,091 1,651 496,820 1,296
Cash received from the acquisition of Gramperfil 13,261
Gramperfil investment acquisition (35,948)
Financial Investments, net of redemption 71,623 8,772 (301) 9,260
Net cash used in financing activities (253,326) (1,214,013) (1,538,634) (629,807)
Borrowings and financing raised 14.b 1,859,743 4,954,349 414,296 910,044
Transactions cost - Borrowings and financing (56,154) (1,180)
Borrowings and financing – related parties 14.b
Amortization of borrowings and financing 14.b (2,793,057) (6,030,948) (1,716,612) (1,535,481)
Amortization of borrowings and financing - related parties 14.b (233,038)
Amortization of leases 16 (92,652) (81,260) (3,280) (3,190)
Dividend anticipation 772,640
Exchange Variation on Cash and Equivalents 57,719 27,598
Increase (decrease) in cash and cash equivalents (1,598,188) (3,522,791) (1,744,383) (2,033,985)
Cash and equivalents at the beginning of the year 14,421,022 23,310,197 3,529,453 5,666,618
Cash and equivalents at the end of the year 12,822,834 19,787,406 1,785,070 3,632,633
The Accompanying notes are an integral part of these consolidation financial statement
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Companhia Siderúrgica Nacional S.A.
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Statements of Value Added
(In thousands of Reais)
Consolidated Parent Company
03/31/2026 03/31/2025 03/31/2026 03/31/2025
Revenues
Sales of products and services rendered 12,047,678 12,423,702 4,705,482 5,487,089
Other income/(expenses) (1,224) 50,998 36,598 44,211
Provision for (reversal of) doubtful debts 4,429 (2,279) (507) (1,358)
12,050,883 12,472,421 4,741,573 5,529,942
Raw materials acquired from third parties
Cost of sales and services (5,742,105) (5,875,760) (3,129,414) (3,377,006)
Materials, electric power, outsourcing and other (1,787,609) (1,576,862) (626,344) (450,945)
Impairment/recovery of assets (162,260) 4,670 (129,507) 4,279
(7,691,974) (7,447,952) (3,885,265) (3,823,672)
Gross value added 4,358,909 5,024,469 856,308 1,706,270
Retentions
Depreciation, amortization and depletion (1,155,156) (999,187) (331,852) (354,423)
Value added created 3,203,753 4,025,282 524,456 1,351,847
Value added received
Equity in results of affiliated companies 23,777 78,434 283,911 89,377
Financial income 327,574 555,056 219,676 248,352
Other and exchange gains 477,003 (1,128,729) 42,064 (44,502)
828,354 (495,239) 545,651 293,227
Value added for distribution 4,032,107 3,530,043 1,070,107 1,645,074
Value added distributed
Personnel and Charges 1,135,673 1,115,768 408,451 410,000
Salaries and wages 895,800 869,604 308,094 306,012
Benefits 188,709 183,750 81,894 78,143
Severance payment (FGTS) 51,164 62,414 18,463 25,845
Taxes, fees and contributions 1,339,200 1,866,390 401,602 863,837
Federal 482,099 911,223 26,029 389,164
State 841,216 949,449 375,573 474,673
Municipal 15,885 5,718
Remuneration on third-party capital 2,112,257 1,279,465 875,586 990,383
Interest 1,413,185 1,269,033 646,602 592,239
Rental 828 2,791 1,711 1,994
Other and exchange losses 698,244 7,641 227,273 396,150
Interest on equity (555,023) (731,580) (615,532) (619,146)
Income for the year/Retained earnings (615,532) (619,146) (615,532) (619,146)
Non-controlling interests 60,509 (112,434)
4,032,107 3,530,043 1,070,107 1,645,074
The Accompanying notes are an integral part of these consolidation financial statement
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Companhia Siderúrgica Nacional S.A.
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Statements of Changes in Equity
(In thousands of Reais)
Capital Legal
Paid-up capital Treasury shares Capital transactions Reserves Retained earnings Other comprehensive income Total Shareholders' Equity Parent Company Non-controlling interest Total Consolidated Shareholders' Equity
Capital Legal Statutory
Balances on December 31, 2024 10,240,000 (223,830) 2,248,080 32,720 1,158,925 640,460 (1,824,917) 12,271,438 3,187,678 15,459,116
Adjusted opening balances 10,240,000 (223,830) 2,248,080 32,720 1,158,925 640,460 (1,824,917) 12,271,438 3,187,678 15,459,116
Total comprehensive income (2,002,374) 2,606,995 604,621 653,088 1,257,709
Net loss (2,002,374) 495,648 495,648
Other comprehensive income 2,606,995 2,606,995 157,440 2,764,435
Actuarial gains/(losses) over pension plan of subsidiaries, net of taxes 50,887 50,887 73 50,960
Cumulative translation adjustments for the year 20,019 20,019 20,019
(Loss)/gain cash flow hedge accounting, net of taxes 2,479,943 2,479,943 2,479,943
Cash flow hedge reclassified to income upon realization, net of taxes (321,341) (321,341) (321,341)
(Loss)/gain cash flow hedge accounting  –  “Platts”  from investments in subsidiaries, net of taxes 350,435 350,435 157,367 507,802
Gain on the percentage change in investments 27,052 27,052 27,052
Allocation of profit/(loss) for the year (1,158,925) (640,460) 1,799,385 (1,052,242) (1,052,242)
Dividends approved of subsidiary (787,905) (787,905)
Interest on equity approved of subsidiary (264,337) (264,337)
Absorption of the loss of the year (1,158,925) (640,460) 1,799,385 -
Capital transactions 71,767 71,767
Constitution of subsidiaries in foreign operations 1,170 1,170
Acquisition of stakes in subsidiaries 70,597 70,597
Balances on December 31, 2025 10,240,000 (223,830) 2,248,080 32,720 - - (202,989) 782,078 12,876,059 2,860,291 15,736,350
Adjusted opening balances 10,240,000 (223,830) 2,248,080 32,720 (202,989) 782,078 12,876,059 2,860,291 15,736,350
Total comprehensive income 887,875 272,344 116,202 388,546
Net loss (615,531) (615,531) 60,508 (555,023)
Other comprehensive income 887,875 887,875 55,694 943,569
Actuarial gains/(losses) over pension plan of subsidiaries, net of taxes (6,138) (6,138) (6,138)
Cumulative translation adjustments for the year (212,235) (212,235) (212,235)
(Loss)/gain cash flow hedge accounting, net of taxes 1,209,621 1,209,621 1,209,621
Cash flow hedge reclassified to income upon realization, net of taxes (270,718) (270,718) (270,718)
(Loss)/gain cash flow hedge accounting  –  “Platts”  from investments in subsidiaries, net of taxes 122,115 122,115 55,694 177,809
Gain on the percentage change in investments 45,230 45,230 45,230
Allocation of profit/(loss) for the year - (615,531) - -
Absorption of the loss of the year
Capital transactions - (298,642) - (298,642) 68,029 (230,613)
Acquisition of joint venture equity interests
Cancellation of treasury shares of subsidiaries (101,551) (101,551)
Acquisition of stakes in subsidiaries 50,979 50,979
Call option on the acquisition of a subsidiary (298,642) (298,642) 118,602 (180,040)
Balances as of March 31, 2026 10,240,000 (223,830) 1,949,438 32,720 - (818,520) 1,669,953 12,849,761 3,044,522 15,894,283
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(In thousands of Reals, unless stated otherwise)

1. DESCRIPTION OF BUSINESS

Companhia Siderúrgica Nacional (“CSN”, “the Company” or “Parent Company”) is a publicly-held corporation, headquartered in the State capital of São Paulo. Founded on April 9, 1941 during the mandate of former Brazilian president Getúlio Vargas, the Company was privatized in 1993.

CSN, together with its subsidiaries, controlled companies, jointly controlled companies and affiliates (referred to as “the Group” or “CSN Group”), operates across five main business segments:

(i) Steel industry: production and commercialization of flat<br>and long steels;
(ii) Mining: extraction, processing and commercialization<br>of iron ore, tin, limestone and dolomite;
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(iii) Cement: production and commercialization of bagged and<br>bulk cement, in addition to aggregates, concrete, and other related products;
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(iv) Energy: generation and sale of energy that is nearly<br>renewably-sourced in entirety; and
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(v) Logistics: participations in railways, port concessions<br>and fleets of road transport vehicles.
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CSN is listed on São Paulo’s B3 S.A. – Brasil, Bolsa, Balcão stock exchange (B3) and the NYSE - United States stock exchange under the codes CSNA3 and SID, respectively. Additionally, its subsidiaries CSN Mineração S.A., FTL - Ferrovia Transnordestina Logística S.A., and Companhia Estadual de Geração de Energia Elétrica – CEEE-G, are publicly traded, and CSN Mineração S.A. makes its common shares available for trading on B3 under the code CMIN3.

CSN Group maintains significantly diverse business areas, and is one of Brazil’s largest steel producers. The company is also the second largest exporter of iron ore and a pioneer in the preparation of tailings piles as part of the dam decommissioning process. In is also Brazil’s second largest player in Brazil’s cement sector.

· Going concern:

Management understands that the Company has adequate resources to continue its operations. Accordingly, these financial statements for the period ended March 31, 2026 were prepared based on the assumption of operational continuity.

2. BASIS OF PREPARATION AND DECLARATION OF CONFORMITY
2.a) Declaration of conformity

The individual and consolidated financial statements ("financial statements") were prepared and are presented in accordance with accounting policies adopted in Brazil issued by the Accounting Pronouncements Committee ("CPC”) and approved by the Brazilian Securities and Exchange Commission ("CVM") and the Federal Accounting Council ("CFC"), and in accordance with International Financial Reporting Standards ("IFRS") issued by the International Accounting Standards Board ("IASB"), currently referred to as IFRS Accounting Standards. All relevant information specific to the financial statements is presented herein, this information is exclusively used by the Company's Management in its operations. The consolidated financial statements are identified as “Consolidated”, and the Parent Company’s individual financial statements are identified as “Parent Company”.

(In thousands of Reals, unless stated otherwise)

2.b) Basis of presentation

The individual and consolidated interim financial information were prepared on a historical cost basis and adjusted to reflect: (i) the fair value measurement of certain financial assets and liabilities (including derivative instruments), as well as pension plan assets; and (ii) impairment losses. Whenever IFRS and CPCs allow for a choice to be made between the acquisition cost or another measurement criterion, the acquisition cost criterion was used.

The preparation of this financial information requires Management to use certain accounting estimates, judgments and assumptions that affect the application of accounting policies and the reported amounts of assets, liabilities, revenues and expenses as of the balance sheet date may differ from actual future results. The assumptions used are based on historical data and other factors considered relevant and are reviewed by the Company's Management.

Interim financial information has been prepared and is presented in accordance with CPC 21 (R1) - "Interim Financial Statement" and IAS 34 - "Interim Financial Reporting" in accordance with the standards established by the CVM. This interim financial information does not include all requirements for annual or complete financial statements and therefore must be read together with the Company's annual financial statements for the year ended December 31, 2025.

In this context, this interim financial information was not repeated either due to redundancy or relevance in relation to information previously presented in the following explanatory notes to the annual financial statements:

Note 2.d - Material accounting policies

Note 2.f - Adoption of new requirements, standards, amendments and interpretations

Note 10.b - Additional information on direct and indirect subsidiaries

Note 10.c - Main occurrences at subsidiaries in 2025 and 2024

Note 12.a - Assets with indefinite useful lives

Note 13 - Impairment of assets

Note 21 - Taxes paid in installments

Note 24.a - Transactions with holding companies

Note 24.c - Other unconsolidated related parties

Note 32 - Employee benefits

Note 33 - Commitments

Note 34 - Insurance

The individual and consolidated financial statements were approved by Management on May 13, 2026.

2.c) Functional Currency and Presentation Currency

The accounting records included in the financial information for each of the Company's subsidiaries are measured using the currency of the main economic environment in which each subsidiary operates ("functional currency"). The Parent Company and Consolidated financial statements are presented in R$ (Brazilian reals), which is the Company's functional currency and the Group's presentation currency.

Transactions in foreign currencies are translated into the functional currency using the exchange rates prevailing on the respective transaction or valuation dates, through which items are remeasured. The balances of the asset and liability accounts are converted at the exchange rate on the balance sheet date. On March 31, 2026, US$1 is equivalent to R$5.2194 (R$5.5024 on December 31, 2025) and €1 is equivalent to R$6.0117 (R$6.4692 on December 31, 2025), according to rates extracted from the website of the Central Bank of Brazil.

(In thousands of Reals, unless stated otherwise)

2.d) Value added statement

According to Federal Law 11.638/07, the presentation of the statement of value added is required for all publicly-held companies. These statements were prepared in accordance with CPC 09 (R1) – Statement of Value Added. IFRS does not require the presentation of this statement; it is therefore presented as additional information.

3. BUSINESS COMBINATION
a) Grupo Estrela
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In 2025, CSN acquired 70% of the share capital of Estrela Comércio e Participações S.A. (“Estrela Group”, “Estrela” or “Tora Group”), in line with its strategy of expansion and integration of logistics operations, focusing on the transport and handling of large volumes of cargo, especially in the mining, steel and cement segments. The transaction strengthens the Company’s position as a logistics operator, enabling it to realize operational synergies and make more efficient use of infrastructure in the regions where the Group operates.

The Estrela Group already had a business relationship with the Company, which contributes to a more efficient integration of operations and maximizes economies of scale.

Acquisition of 70% Estrela Comércio e ParticipaçõesS.A.’s share capital. (Grupo Estrela)

On April 1, 2025, the Company completed the acquisition of 70% of the share capital of Estrela Comércio e Participações S.A., holding company of the road and multimodal logistics group known as TORA Group. The initial value of the transaction was R$742,500, of which R$300,000 was paid on the closing date and the remaining balance to be settled in three annual installments: R$111,250 on April 1, 2026, R$111,250 on April 1, 2027 and R$220,000 on April 1, 2028.

In September 2025, an additional payment of R$9,994 was made, referring to the purchase price adjustment. Thus, the total nominal amount of the operation became R$752,494.

Estrela is the parent company of several operating companies that provide road and intermodal logistics services, warehousing, equipment leasing, and related services, including Tora Transportes Ltda., Tora Locações S.A., FJX Transportes S.A., N. Minas Transportes e Locações Ltda., Saratoga Transportes Ltda., Lokamig Rent a Car S.A., Seminovos Lokamig Ltda., Tora Logística Armazéns e Terminais Multimodais S.A., Tora Recintos Alfandegários S.A., and Tora Seminovos Comércio de Veículos Ltda., which have become part of the Company’s group of indirect subsidiaries.

For accounting purposes, the Company was identified as the acquirer, having obtained control of Estrela on the acquisition date, based on its 70% ownership of the voting capital and its ability to direct Estrela’s financial and operational policies. Consequently, Estrela and its subsidiaries have been fully consolidated in the Company’s financial statements effective April 1, 2025.

(In thousands of Reals, unless stated otherwise)

(i) Determining purchase price

In accordance with CPC 15 (R1) / IFRS3, the purchase price is determined by the sum of the transferred assets, liabilities incurred, equity interests issued, non-controlling interests and the fair value of any interest held prior to the transaction.

Percentage Acquired and Voting Capital

Estrela’s fully subscribed and paid-up share capital as of the acquisition date, consists of 229,993,768 registered common shares without par value. A majority interest, equivalent to 70% of Estrela’s share capital, was acquired during the transaction in question.

Calculation of Consideration Transferred and to be Transferred (“Transaction Amount”)

The fair value of the transaction on the date of the Combination totaled R$ 738,068, consisting of a lump-sum payment and three deferred installments, broken down as follows:

Description Nominal Fair value of the consideration
in cash ^(1)^ 309,994 309,994
1st Deferred Payment 111,250 107,466
2nd Deferred Payment 111,250 108,354
3rd Deferred Payment 220,000 212,254
Total 752,494 738,068

(1) This includes the amount of R$ 300,000 paid in April plus the R$ 9,994 paid in September, both in 2025.

(ii) Fair value ofassets acquired and liabilities assumed

The table below shows the allocation of provisional and final amounts of assets acquired and liabilities assumed on April 1, 2025, calculated based on reports from independent appraisers.

(In thousands of Reals, unless stated otherwise)

Provisional amounts Adjustment to provisional amounts Fair value (Final)
Fair value of acquired assets:
Current Assets
Cash and cash equivalents 87,046 1,328 88,374
Trade receivables ^(1)^ 205,529 205,529
Inventories 72,924 72,924
Recoverable taxes 18,672 18,672
Other current assets 26,561 1,946 28,507
Non-Current Asset
Deferred Taxes ^(8)^ 47,393 47,393
Other non-current assets 21,122 21,122
Indemnity assets^(2)^ 51,370 51,370
Prosperty, plant and equipament ^(3)^ 820,398 136,436 956,834
Intangible assets ^(4)^ 71,591 287,513 359,104
1,371,236 478,593 1,849,829
Fair value of assumed liabilities:
Current Liabilities
Trade payables 180,962 180,962
Borrowings and financing ^(5)^ 251,201 251,201
Payroll and related taxes 29,600 29,600
Lease liabilities ^(6)^ 19,633 19,633
Other payables 34,177 34,177
Non-current Liabilities
Borrowings and financing ^(5)^ 378,655 5,403 384,058
Lease liabilities ^(6)^ 189,545 189,545
Provisions for tax, social, labor civil, environmental risk ^(7)^ 24,828 48,558 73,386
Deferred income tax ^(8)^ 32,709 32,709
Other payables 7,510 2,156 9,666
1,148,820 56,117 1,204,937
Total of identifiable net assets at fair value 222,416 422,476 644,892
70% ownership by the Controller 155,691 311,143 466,834
30% non-controlling ownership ^(9)^ 66,725 111,333 178,058

(1) The fair value of accounts receivable totals R$ 205,529, which is equal to their carrying amount, and it is expected that the full amount of the contractual amounts will be collected.

(2) Pursuant to the purchase agreement and the shareholders’ agreement, the sellers are liable to pay the Company compensation up to the amount of R$ 300,000, which is subject to adjustment based on the CDI rate as of the date of the Business Combination. Indemnity from and against any losses suffered or incurred.

(3) The fair value of fixed assets determined by market and cost approaches, mainly for vehicle groups (light and heavy-duty, dump trucks and semi-trailers), machinery and equipment and improvements.

(4) The fair value of intangible assets includes intangible assets acquired and recognized by the Acquired Company prior to the fair value allocation, in the amount of R$ 49,862, plus the effects of the fair value allocation described below:

(In thousands of Reals, unless stated otherwise)

Fair Value Service life (in years)
Brands^a^
Lokamig 13,389 16
Customer Portfolio ^b^
Tora Transportes 153,206 19
Tora Logistica 55,418 10
Tora Recintos 37,552 3
FJX 32,293 13
Lokamig 17,384 2
Total 309,242

(a) Represents the fair value of the Lokamig brand. The method used to determine the royalty was based on comparable royalty transactions, as well as the relative importance of the respective brand to the Acquired Company’s revenue generation.

(b) Represents the fair values of the Customer Portfolios. The income approach used the MPEEM (Multi-Period Excess Earnings Method), based on net operating revenue. For expenses, costs, expenses, depreciation, and taxes related to operations were deducted, and advertising and promotional costs were added.

(5) The Loans and financing assumed in the acquisition and their respective maturities are shown in the tables below:

Current Liabilities Non-current Liabilities Total
Debt contracts in the foreign market
Fixed interest in US
Bonds, Facility and ACC 35,277 38,500 73,777
35,277 38,500 73,777
Debt contracts in national currency
R
BNDES/FINAME/FINEP, Debentures, CRI and NCE 215,924 345,558 561,482
215,924 345,558 561,482
Total Borrowings and Financing 251,201 384,058 635,259

All values are in US Dollars.

Maturity Foreign currency loans Loans in National Currency Total
2025 82,513 82,513
2026 35,277 176,201 211,478
2027 151,109 151,109
2028 38,500 49,128 87,628
2029 15,167 15,167
2030 87,364 87,364
73,777 561,482 635,259

(6)  The Company measured acquired lease liabilities using the present value of the remaining lease payments as of the acquisition date. Right-to-use assets were measured at an amount equal to lease liabilities and adjusted, when necessary, to reflect favorable lease conditions relative to market terms.

(7)   Provisions and contingent liabilities assumed in the acquisition that were considered present obligations arising from past events and can be reliably measured have been recognized and are initially measured at fair value on the acquisition date and subsequently measured in accordance with the requirements of IFRS 3 (CPC 15 (R1)), at an amount in excess of that which would be recognized in accordance with IAS 37 (CPC 25). The table shown below presents the total amount of provisions and contingent liabilities assumed on the transaction date, including attributed fair value, as follows:

R$
Tax 19,549
Labor 53,793
Civil 44
73,386

(8) Consists mainly of deferred tax liabilities related to the initial balance of the Acquired

(9) Measured as the proportionate share, at fair value, of the acquiree’s identifiable net assets.

(In thousands of Reals, unless stated otherwise)

(iii) Goodwill on acquisitionof control

In accordance with item 32 of CPC15 (R1)/IFRS3, the acquiror must recognize goodwill for expected future profitability as of the acquisition date, which is measured according to the amount by which the purchase price exceeds the fair value of assets and liabilities acquired (allocation of the purchase price). The transaction generated goodwill based on expected future profitability, as shown in the table below:

Description Reference R$
Total purchase price A (i) 738,068
Participation of Non-Controlling Interests B (ii) 178,058
Fair value of net assets C (iiI) 644,892
Ágio^1^ (goodwill) = ( A + B - C ) 271,234

(1) Goodwill was mainly attributable to:

· Expected operational and logistical synergies;
· Vertical integration of transport operations<br>within the CSN Group;
--- ---
· Gains in scale and efficiency;
--- ---
· Capacity to expand within the logistics<br>market;
--- ---
· Additionally, expected future profitability.
--- ---

Goodwill arising from the transaction is expected to result in a tax benefit, i.e., to be deductible for tax purposes.

Goodwill is part of the investment’s carrying amount. In the Consolidated Financial Statements, goodwill is recognized as an intangible asset and, because it has an indefinite useful life, is not amortized, in accordance with CPC 04 (R1)/IAS 38; it is tested for impairment at least annually.

(iv) Other disclosures:revenue and results

Grupo Estrela
Period (from - to) a 04/01/2025 to 12/31/2025
Revenue 763,412
P&L (16,912)
Period (from - to) b 01/01/2025 to 12/31/2025
Revenue 1,019,278
P&L (36,778)
(a) Impact on the Company's consolidated<br>financial statements (“FSs") in fiscal year 2025
--- ---
(b) Impact on FSs if the acquisition date<br>had occurred at the start of the 2025 fiscal year
--- ---
b) Galvacolor, Gramperfil and Global Dot
--- ---

In 2025, the Company completed the acquisition of control of the companies Global Dot Com S.A. ("Global Dot"), Galvacolor Jerez S.L.U. ("Galvacolor") and Gramperfil, S.A. ("Gramperfil"), operations that may be considered business combinations.

(In thousands of Reals, unless stated otherwise)

These acquisitions were performed in line with the strategy of expanding and strengthening the Company's presence in the steel processing market segments and added greater value to the production chain while expanding commercial capillarity and enhancing operational, industrial, and logistical synergies.

(i) Preliminary GeneralInformation on Acquisitions

Galvacolor ^(1)^ Gramperfil ^(2)^ Globaldot ^(3)^
Acquisition date 11/18/2025 03/23/2025 5/12/2025
Percentage ("%") acquired of the share capital 100% 90% 80%
Price paid (Consideration transferred) - R$ 291,013 73,128 50,891

(1) Galvacolor, which was acquired by CSN Steel S.L., maintains industrial operations dedicated to the galvanization and painting of flat steels. The company largely maintains operations in the civil construction sector. This transaction expanded the Company's portfolio of coated products and strengthens its competitive positioning on the European market.

(2) Gramperfil, which was acquired by CSN Steel S.L., specializes in the manufacture of metal structural profiles and accessories used in the construction sector. This acquisition allows the Company to expand its operations in the market segment for structural solutions and offers greater proximity to end customers and an increase in operating margin.

(3) Global Dot, which was indirectly acquired by CSN through its subsidiaries CSN Inova Ventures and CSN Inova Soluções S.A., provide complete fleet management services with a focus on improving internal logistics and improving processes used in making requests, scheduling, execution, measuring contracts and sizing fleets. This acquisition is in line with the Company's integration strategy, aiming at provided greater synergy, productivity and reducing costs through a single technological platform.

(ii) Provisional fair value of assets acquired and liabilities assumed
Galvacolor Gramperfil Total
--- --- --- ---
Fair value of acquired assets:
Current Assets
Cash and cash equivalents 4,914 13,261 18,175
Trade receivables 42,285 23,704 65,989
Inventories 193,943 23,621 217,564
Recoverable taxes 24,087 1,809 25,896
Other current assets 2,346 1,360 3,706
Non-current Assets
Deferred taxes 3,210 3,210
Other non-current assets 51 22 73
Property, plant and equipment 167,685 30,389 198,074
Intangíible assets 46 42 88
438,567 94,208 532,775
Fair value of assumed liabilities:
Current Liabilities
Trade payables 115,669 7,017 122,686
Borrowings and financing - 11,718 11,718
Taxes payable 26,947 2,143 29,090
Other payables 4,938 202 5,140
147,554 21,080 168,634
Total of identifiable net assets at fair value 291,013 73,128 364,141

Due to the acquisition of Global Dot on December 5, 2025, the Company began the contracting process for the allocation of the purchase price (PPA) in 2026 in order to identify and measure the assets acquired and liabilities assumed at fair value. For preliminary disclosure purposes, the amount initially recognized as fair value for acquired assets is considered the book value of the acquiree's equity on the transaction base date. This amount totals R$ 11,728 and is subject to adjustments arising from the completion of the fair value measurement process, which may impact the final value of the goodwill recognized.

(In thousands of Reals, unless stated otherwise)

(iii) Provisional goodwill on acquisition of control
Galvacolor Gramperfil Globaldot
--- --- --- --- ---
Total acquisition price A 291,013 73,128 50,891
Fair value of net assets B 291,013 73,128 11,728
Goodwill ^(1)^ = ( A - B ) 39,163

(1) Provisional goodwill recognized in acquisitions is mainly attributed to:

· Expected operational and commercial synergies;
· Gains in scale;
--- ---
· Logistics integration;
--- ---
· Specialized workforce;
--- ---
· Expansion of market presence;
--- ---
· additionally, expected future profitability
--- ---

Goodwill arising from the transaction is expected to result in a tax benefit, i.e., to be deductible for tax purposes.

(iv) Other disclosures:revenue and results

Galvacolor Gramperfil Global Dot*
Period (from - to) a 11/18/2025 to 12/31/2025 03/23/2025 to 12/31/2025 12/05/2025 to 12/31/2025 Total
Revenue 18,301 80,886 99,187
P&L (4,543) 5,328 785
Period (from - to) b 01/01/2025 to 12/31/2025 01/01/2025 to 12/31/2025 01/01/2025 to 12/31/2025 Total
Revenue 315,216 113,179 26,349 454,744
P&L (75,802) 6,299 9,838 (59,665)

(*) Considering that the acquisition was completed on December 5, 2025 and there were no material transactions made in the last month of the year, there was no impact on the Company's financial statements.

(a) impact on the Company's consolidated<br>financial statements (“FSs") in fiscal year 2025
(b) impact on FSs if the acquisition date<br>had occurred at the start of the 2025 fiscal year
--- ---
c) Measurement and Appraisal Reports related to BusinessCombinations
--- ---

As of the date of these financial statements, the process of measuring and preparing fair value appraisal reports for the identifiable assets acquired and liabilities assumed—including separable intangible assets—is currently underway with independent appraisers, in accordance with the measurement period of up to 12 months. Therefore, the amounts recognized are provisional and may be subject to minor adjustments upon completion of the purchase price allocation (PPA) reports, except in the case of the Estrela Group, for which the valuation report has been finalized. For this case, the Company concluded that it obtained the necessary information about the facts and circumstances existing on the acquisition date, and there is no additional relevant information to be obtained.

(In thousands of Reals, unless stated otherwise)

4. CASH AND CASH EQUIVALENTS
Consolidated Parent Company
--- --- --- --- ---
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Cash and banks
In Brazil 1,659,902 1,178,037 38,251 308,969
Abroad 4,577,403 5,626,095 38,447 61,089
6,237,305 6,804,132 76,698 370,058
Financial investments
In Brazil 4,294,851 5,509,312 1,708,372 3,159,395
Abroad 2,290,678 2,107,578
6,585,529 7,616,890 1,708,372 3,159,395
12,822,834 14,421,022 1,785,070 3,529,453

The financial resources available in the country are primarily invested in private and public securities with income linked to the variation of Interbank Deposit Certificates (CDI) and repurchase and resale agreements backed by fixed income securities. The Company applies part of the resources through exclusive investment funds, whose financial statements were consolidated in the Company.

Overseas financial resources are held in dollars and euros and are invested in TD (Time Deposit) transactions at pre-fixed rates as well as in accounts subject to automatic remuneration and daily liquidity. Yields are pegged to FED Funds and the ECB’s deposit rate. Bank counterparties are considered to be first-rate by Management.

5. FINANCIAL INVESTMENTS
Consolidated Parent Company
Current Non-current Current Non-current
03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Investments ^(1)^ 198,083 270,318 25,867 25,257 8,878 8,577
Usiminas shares ^(2)^ 418,628 372,397 418,628 372,397 -
616,711 642,715 25,867 25,257 427,506 380,974 -

(1) These are financial investments in restricted categories, linked to Bank Deposit Certificates (CDBs) to secure letters of guarantee with financial institutions, as well as investments in government securities (LFT – Treasury Bills), managed by dedicated funds, totaling R$ 27,620. The subsidiary CSN Cimentos Brasil holds restricted financial investments intended to secure a liability with an indefinite maturity date. The balance was R$ 3,903 as of March 31, 2026 (R$ 3,649 as of December 31, 2025). The subsidiaries Estanho de Rondônia S.A. and Elizabeth Cimentos S.A. have investments tied to financing agreements, maturing in 2028 and 2030, respectively, totaling R$ 21,964 (R$ 21,214 as of December 31, 2025). In the consolidated financial statements, there is also a financial investment of R$ 170,463 from CSN Steel S.L.U., related to the acquisition of Galvacolor, with a maturity date scheduled for November 2026.

(In thousands of Reals, unless stated otherwise)

6. TRADE RECEIVABLES
Consolidated Parent Company
Ref. 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Trade receivables
Third parties
In Brazil 1,550,811 1,241,180 836,460 615,807
Abroad 1,495,911 1,304,707 58,283 9,829
3,046,722 2,545,887 894,743 625,636
(-) Estimated losses with doubtful liquidation credits (239,238) (246,153) (108,435) (109,746)
2,807,484 2,299,734 786,308 515,890
Related parties 22.a 90,392 97,299 1,314,693 1,186,355
2,897,876 2,397,033 2,101,001 1,702,245

The composition of the gross balance of accounts receivables from third party customers is shown as follows:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Current 2,565,678 1,928,230 762,704 485,412
Past-due up to 30 days 187,757 322,295 4,367 9,253
Past-due up to 180 days 75,117 71,947 13,909 16,870
Past-due over 180 days 218,170 223,415 113,763 114,101
3,046,722 2,545,887 894,743 625,636

The changes in expected credit losses are as follows:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Opening balance (246,153) (212,088) (109,746) (95,617)
(Loss)/Reversal estimated 4,429 (32,660) (506) (18,923)
Recovery of receivables 2,486 6,164 1,817 4,794
Acquisition of stakes in subsidiaries (7,569)
Closing balance (239,238) (246,153) (108,435) (109,746)

The Company carries out credit assignment operations without co-obligation. After the assignment of the customer's trade bills/securities and receipt of the proceeds from the closing of each transaction, CSN settles the related receivables and fully discharges the credit risk of the transactions. Financial expenses related to the credit assignment transaction for the period ended March 31, 2026, amounted to R$ 20,242 (as of March 31, 2025, R$ 13,895) on a consolidated basis and R$ 18,656 (as of December 31, 2025, R$ 9,511) for the parent company, classified in financial income.

(In thousands of Reals, unless stated otherwise)

7. INVENTORIES
Consolidated Parent Company
--- --- --- --- ---
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Finished goods 3,103,769 3,565,541 1,694,017 1,932,948
Work in progress 4,643,716 4,515,197 2,154,575 2,035,686
Raw materials 2,826,838 2,804,157 1,657,492 1,502,000
Storeroom supplies 1,726,760 1,649,866 740,169 700,716
Advances to suppliers 102,014 99,325 62,049 60,045
(-) Provision for losses (96,155) (105,060) (24,733) (25,907)
12,306,942 12,529,026 6,283,569 6,205,488
Classified:
Current 10,170,174 10,455,500 6,283,569 6,205,488
Non-current ^(1)^ 2,136,768 2,073,526
12,306,942 12,529,026 6,283,569 6,205,488

(1) Long-term inventories of iron ore that will be processed when implementing new processing plants, which will generate Pellet Feed as a final product. The start of operations is scheduled for the fourth quarter of 2027.

The changes in expected losses on inventories are as follows:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Opening balance (105,060) (149,927) (25,907) (36,835)
Reversal/(Provision for losses) on inventories with low turnover and obsolescence 8,905 44,867 1,174 10,928
Closing balance (96,155) (105,060) (24,733) (25,907)
8. RECOVERABLE TAXES
--- ---
Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
ICMS (Brazilian State Value-Added Tax) 2,369,308 2,323,633 1,589,030 1,570,468
Brazilian federal taxes ^(1)^ 2,871,959 2,846,259 1,663,859 1,652,207
Other taxes 207,388 183,442 34,014 30,110
5,448,655 5,353,334 3,286,903 3,252,785
Classified:
Current 1,666,038 1,376,434 564,702 511,925
Non-current 3,782,617 3,976,900 2,722,201 2,740,860
5,448,655 5,353,334 3,286,903 3,252,785

(1) The Brazilian federal tax balance mainly refers to PIS and COFINS, IRPJ and CSLL and IPI.

Accumulated tax credits generally derive from ICMS, PIS and COFINS credits on purchases of inputs and property, plant, and equipment used in production. The realization of these credits generally occurs through offsetting with debits of these taxes, generated by sales operations and other taxed outputs.

Due to the mining industry’s predominantly export-oriented nature, there was an increase in the balance of ICMS, PIS, and COFINS credits during the period, primarily attributable to CAPEX investments made as part of the Congonhas Mining Expansion Project, as well as the purchase of ore from third parties.

The balance of recoverable taxes maintained in the short term is expected to be offset in the next 12 months.

(In thousands of Reals, unless stated otherwise)

Based on budget analyses and projections approved by Management, there is no forecast of risks regarding the non-realization of these tax credits, provided that such budget projections materialize.

9. OTHER CURRENT AND NON-CURRENT ASSETS
Consolidated Parent Company
--- --- --- --- --- --- --- --- --- ---
Current Non-current Current Non-current
Ref. 03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Judicial deposits 20 620,990 621,012 225,639 226,793
Derivative transactions 14.a 7,455 494 3,375
Dividends receivable 22.a 217,746 76,026 400,443 1,167,342
Prepaid expenses 581,648 493,924 11,188 14,732 315,893 259,173 9,547 13,093
Actuarial asset 22.a 54,946 53,328 42,410 41,138
Receivables from related parties 22.a 4,775 5,978 1,663,922 2,137,882 204,556 177,324 3,084,540 3,474,388
Loans with related parties ^(1)^ 2,944 4,147 1,663,922 2,137,882 2,944 4,147 3,084,540 3,474,388
Other receivables from related parties 1,831 1,831 - 201,612 173,177 -
Other assets 406,611 461,503 1,065,201 1,024,408 291,633 263,926 1,042,501 1,001,099
Trading securities 3,079 2,598 2,876 2,408
Compulsory loans from Eletrobrás 3,787 678
Employee debts 140,569 120,327 78,753 64,047
Receivables by indemnity ^(2)^ 840,536 779,827 840,536 779,827
Receivables - Usiminas Shares 204,852 192,911 150,578 150,578 204,852 192,911 150,578 150,578
Advances to suppliers 1,200 2,820
Others 56,911 142,847 74,087 90,216 5,152 4,560 51,387 70,016
1,218,235 1,037,925 3,416,247 3,851,362 1,215,900 1,867,765 4,404,637 4,756,511

(1) On March 31, 2026, Transnordestina Logística S.A. made a partial payment on the loan owed to CSN, in the amount of R$ 495,425. (See note 22.a)

(2) Non-current assets are composed of liquidated and certain credit arising from an final and unappealable ruling issues in the Company’s favor, mainly due to losses and damages resulting from a drop in voltage in the energy supply during periods between January/1991 and June/2002.

10. BASIS OF CONSOLIDATION AND INVESTMENTS

The accounting policies have been consistently applied to all consolidated companies. The consolidated financial statements for the period ended March 31, 2026 and 2025 include the following subsidiaries and joint ventures, direct and indirect, affiliates, in addition to the exclusive funds, as shown below:

(In thousands of Reals, unless stated otherwise)

Equity interests (%)
Companies 03/31/2026 12/31/2025 Core business
Direct interest in subsidiaries
CSN Islands VII Corp. 100.00 100.00 Financial transactions
CSN Inova Ventures 100.00 100.00 Equity interests and financial transactions
CSN Islands XII Corp. 100.00 100.00 Financial transactions
CSN Steel S.L.U. 100.00 100.00 Equity interests and financial transactions
TdBB S.A ^(*)^ 100.00 100.00 Equity interests
Sepetiba Tecon S.A. 99.99 99.99 Port services
Minérios Nacional  S.A. 99.99 99.99 Mining and Equity interests
Companhia Florestal do Brasil 99.99 99.99 Reforestation
Estanho de Rondônia S.A. 99.99 99.99 Tin Mining
Companhia Metalúrgica Prada 99.89 99.89 Manufacture of containers and distribution of steel products
CSN Mineração S.A.^(2)^ 69.69 69.01 Mining
CSN Energia S.A. 99.99 99.99 Sale of electric power
FTL - Ferrovia Transnordestina Logística S.A. 92.71 92.71 Railroad logistics
Nordeste Logística S.A. 99.99 99.99 Port services
CSN Inova Ltd. 100.00 100.00 Advisory and implementation of new development project
CBSI - Companhia Brasileira de Serviços de Infraestrutura 99.99 99.99 Equity interests and product sales and iron ore
CSN Cimentos Brasil S.A. 99.99 99.99 Cement manufacturing
Berkeley Participações e Empreendimentos S.A. 100.00 100.00 Electric power generation and equity interests
CSN Inova Soluções S.A. 99.99 99.99 Equity interests
CSN Participações I S.A. 99.90 99.90 Equity interests
Circula Mais Serviços de Intermediação Comercial S.A. 0.10 0.10 Commercial intermediation for the purchase and sale of assets and materials in general
CSN Participações III S.A. 99.90 99.90 Equity interests
CSN Participações IV S.A. 99.90 99.90 Equity interests
CSN Participações V S.A. 99.90 99.90 Equity interests
CSN Incorporação e Participações Ltda. 99.99 99.99 Equity interests
Estrela Comércio e Participações S.A. 70.00 70.00 Equity interests
Indirect interest in subsidiaries
Lusosider Projectos Siderúrgicos S.A. 100.00 100.00 Equity interests and product sales
Lusosider Aços Planos, S. A. 100.00 100.00 Steel and Equity interests
CSN Resources S.A. 100.00 100.00 Financial transactions and Equity interests
Companhia Brasileira de Latas 99.89 99.89 Sale of cans and containers in general and Equity interests
Companhia de Embalagens Metálicas - MMSA 99.88 99.88 Production and sale of cans and related activities
Companhia de Embalagens Metálicas - MTM 99.88 99.88 Production and sale of cans and related activities
CSN Productos Siderúrgicos S.L. ^(1)^ - 100.00 Financial transactions, product sales and Equity interests
Stalhwerk Thüringen GmbH 100.00 100.00 Production and sale of long steel and related activities
CSN Steel Sections Polska Sp.Z.o.o 100.00 100.00 Financial transactions, product sales and Equity interests
CSN Mining Holding, S.L.U. ^(2)^ 69.69 69.01 Financial transactions, product sales and Equity interests
CSN Mining GmbH ^(2)^ 69.69 69.01 Financial transactions, product sales and Equity interests
CSN Mining Asia Limited ^(2)^ 69.69 69.01 Commercial representation
Lusosider Ibérica S.A. 100.00 100.00 Steel, commercial and industrial activities and equity interests
Companhia Siderúrgica Nacional, LLC 100.00 100.00 Import and distribution/resale of products
Elizabeth Cimentos S.A. 99.99 99.99 Cement manufacturing
Santa Ana Energética S.A. 99.99 99.99 Electric power generation
Topázio Energética S.A. 99.99 99.99 Electric power generation
Brasil Central Energia Ltda. 99.99 99.99 Electric power generation
Circula Mais Serviços de Intermediação Comercial S.A. 99.90 99.90 Commercial intermediation for the purchase and sale of assets and materials in general
Metalgráfica Iguaçu S.A 99.89 99.89 Metal packaging manufacturing
Companhia Energética Chapecó  - CEC ^(2)^ 69.69 69.01 Electric power generation
Companhia Estadual de Geração de Energia Elétrica - CEEE-G 100.00 100.00 Electric power generation
Ventos de Vera Cruz S.A. 99.99 99.99 Electric power generation
Ventos de Curupira S.A. 99.99 99.99 Electric power generation
Ventos de Povo Novo S.A. 99.99 99.99 Electric power generation
MAZET Maschinenbau und Zerspanungstechnik Unterwellwnborn GmbH 100.00 100.00 Production and sale of long steel and related activities
CSN ITC Solutions AG ^(2)^ 55.75 55.21 Financial transactions, product sales and Equity interests
CSN Mining International GmbH ^(2)^ 69.69 69.01 Commercial and representation of products
Gramperfil S.A. 90.00 90.00 Manufacturing and sale of metal profile
CSN International Steel GmbH 100.00 100.00 Commercial and representation of products
Tora Transportes Ltda^^ 70.00 70.00 Road transport
Tora Locações S.A. 70.00 70.00 Road transport and automobile rental
FJX Transportes S.A.^^ 42.00 42.00 Road transport and logistic
N. Minas Transportes e Locações Ltda. 70.00 70.00 Road transport and logistic
Saratoga Transportes Ltda 70.00 70.00 Road transport
Lokamig Rent a Car S.A. 70.00 70.00 Automobile rental
Seminovos Lokamig Ltda. 70.00 70.00 Automobile rental
Tora Logística Armazéns e Terminais Multimodais S.A. 70.00 70.00 Logistics
Tora Recintos Alfandegários S.A.^^ 70.00 70.00 General storage operations and road transport
Tora Seminovos Comércio de Veículos Ltda. 70.00 70.00 Commercial and automobile rental
CSN Captive Insurance Company, LLC^^ 100.00 100.00 Captive Insurance Company
Global Dot Com S.A 80.00 80.00 Information service provision
Galvacolor Jerez S.L.U.^^ 100.00 100.00 Transformation and commercialization of steel products
Direct interest in joint operations
Itá Energética S.A. 48.75 48.75 Electric power generation
Direct interest in joint ventures: equity method
MRS Logística S.A. 7.59 7.59 Railroad transportation
Aceros Del Orinoco S.A. ^(*)^ 31.82 31.82 Dormant company
Transnordestina Logística S.A.^^ 33.89 33.89 Railroad logistics
Equibras S.A 50.00 50.00 Rental of commercial and industrial machinery and equipment
Indirect interest in joint ventures: equity method
MRS Logística S.A. 20.84 20.64 Railroad transportation
Direct interest in associates: equity method
Arvedi Metalfer do Brasil S.A. 20.00 20.00 Metallurgy and Equity interests
Panatlântica S.A. 29.92 29.92 Steel
Indirect interest in affiliates: equity method
Jaguari Energética S.A. 10.50 10.50 Electric power generation
Chapecoense Geração S.A. 9.00 9.00 Electric power generation
Companhia Energética Rio das Antas - Ceran 30.00 30.00 Electric power generation
Foz Chapecó Energia S.A. 9.00 9.00 Electric power generation
Exclusive Funds
Diplic II  - Private credit balanced mutual fund 100.00 100.00 Investment fund
Caixa Vértice - Fundo de investimento multimercado crédito privado Longo Prazo 100.00 100.00 Investment fund
VR1 - Private credit balanced mutual fund 100.00 100.00 Investment fund
Consortiuns
Consórcio Itaúba 99.99 99.99 Electric power generation
Consórcio Passo Real ^(2)^ 96.63 96.55 Electric power generation
Consórcio da Usina Hidrelétrica de Igarapava 17.92 17.92 Electric power generation
Consórcio Dona Francisca 15.00 15.00 Electric power generation
---

(In thousands of Reals, unless stated otherwise)

(*) Dormant companies.

(1) CSN Productos Siderúrgicos S.L.U. was merged into CSN Steel S.L.U., pursuant to the Deed of Merger dated March 3, 2026, with the consequent transfer of all its rights, duties and obligations to CSN Steel S.L.U.

(2) On March 27, 2026, the Board of Directors of CSN Mineração S.A. ("CMIN") approved the cancellation of 53,294,297 common, registered, book-entry shares with no par value, issued by CMIN held in treasury, without reducing the share capital. As a result of this resolution, Companhia Siderúrgica Nacional's direct shareholding in CMIN went from 69.01% to 69.69%.

10.a) Changes in Investments inControlled Companies, Joint-Venture, Joint- operations, Affiliates, and Other Investments

The positions presented on March 31, 2026 and December 31, 2025 refer to the interest held by CSN in these companies:

Consolidated
Companies Final balance on 12/31/2025 Dividends Equity Income Comprehensive income Others Final balance on 03/31/2026
Investments under the equity method
Joint-venture, Joint-operation and Affiliate
MRS Logistica 3,382,093 (138,555) 29,189 3 3,272,730
Fair Value MRS 480,622 480,622
Fair Value MRS amortization (117,464) (2,937) (120,401)
Transnordestina Logística S.A.^^ 2,916,482 1,444 2,917,926
Fair Value -Transnordestina 659,106 659,106
Arvedi Metalfer do Brasil S.A. 34,601 34,601
Panatlântica S.A. 219,555 (3,539) 5,935 221,951
Equibras S.A. 39,054 (632) 38,422
Indirect interest in affiliates - CEEE-G 144,250 14,490 158,740
Fair Value indirect participation CEEE-G 319,709 319,709
Fair Value amortization indirect participation CEEE-G (60,941) (2,094) (63,035)
8,017,067 (142,094) 45,395 3 7,920,371
Other participations
Global Dot 11,728 (3,214) (8,514)
Others 43,706 (938) 42,768
55,434 (3,214) (9,452) 42,768
Total shareholdings 8,072,501 (142,094) 42,181 3 (9,452) 7,963,139
Classification of investments in the balance sheet
Equity interests 8,072,501 7,963,139
Investment Property 219,525 218,512
Total investments in the asset 8,292,026 8,181,651
Consolidated
--- --- --- --- --- --- --- --- ---
Companies Final balance on 12/31/2024 Capital increase and (Decrease)/acquisition of shares Write-offs Transfers Dividends Equity Income Comprehensive income Final balance on 12/31/2025
Investments under the equity method
Joint-venture, Joint-operation and Affiliate
MRS Logistica 2,799,168 583,027 (102) 3,382,093
Fair Value MRS 480,622 480,622
Fair Value MRS amortization (105,719) (11,745) (117,464)
Transnordestina Logística S.A. ^(1)^ 1,137,345 1,792,580 (18,129) 4,686 2,916,482
Fair Value -Transnordestina 659,106 659,106
Arvedi Metalfer do Brasil S.A. 35,257 (656) 34,601
Panatlântica S.A. 225,764 (19,477) 13,268 219,555
Equibras S.A. ^(2)^ 31,733 (2,187) 9,508 39,054
Indirect interest in affiliates - CEEE-G 146,753 (44,846) 42,343 144,250
Fair Value indirect participation CEEE-G 319,709 319,709
Fair Value amortization indirect participation CEEE-G (42,523) (18,418) (60,941)
5,687,215 1,792,580 (66,510) 599,198 4,584 8,017,067
Other participations
Global Dot ^(3)^ 1,685 10,043 11,728
Others ^(4)^ 58,796 (9) (5,038) (10,043) 43,706
58,796 1,676 (5,038) 55,434
Total shareholdings 5,746,011 1,794,256 (5,038) (66,510) 599,198 4,584 8,072,501
Classification of investments in the balance sheet
Equity interests 5,746,011 8,072,501
Investment Property 202,040 219,525
Total investments in the asset 5,948,051 8,292,026

(1) Paying in of AFACs by CSN on October 17, 2025.

(In thousands of Reals, unless stated otherwise)

(2) Equimac S.A. changed its corporate name in December 2025 to "Equibras S.A.", with no change in the Company's interest in this company.

(3) On December 5, 2025, the Company acquired control of Global Dot Com S.A. (“Global Dot”) and came to indirectly hold 80% of the company’s share capital through the subsidiaries CSN Inova Ventures (2.51%) and CSN Inova Soluções S.A. (77.49%). The acquisition was carried out through the conversion of a loan into shares, as well as the purchase of an additional interest totaling R$ 49.9 million. The Company previously held an investment in Global Dot, which was controlled at fair value. Located in the municipality of Barueri/SP, Global dot is incorporated as a corporation and aims to provide information services, especially fleet management services via integrated software.

(4) These strategic investments were made in startups by the subsidiary CSN Inova Ventures, either through the execution of a convertible loan with Alinea Health Holdings Ltda., or through an participation in the following companies: I Systems Automação Industrial S.A., H2Pro Ltda., 1S1 Energy Inc., Traive Inc. and Oico Holdings Limited.

The reconciliation of equity income at jointly controlled entities classified as joint ventures and affiliates and the amount presented in the income statement is presented below, as well as profit and loss stemming from the elimination of CSN’s transactions with these companies:

Consolidated
03/31/2026 03/31/2025
Equity in results of affiliated companies
MRS Logística S.A. 29,189 105,997
Transnordestina Logística S.A. 1,444 (7,333)
Arvedi Metalfer do Brasil S.A. 458
Equibras S.A. (632) 2,544
Indirect interest in affiliates - CEEE-G 14,490 (1,922)
Panatlântica S.A. 5,935 4,287
Fair Value Amortization (5,031) (8,218)
45,395 95,813
Reclassification IAS 28 ^(1)^ (17,801) (17,487)
Others (3,817) 108
Equity in results 23,777 78,434

(1) The operating margin of intercompany operations carried out with group companies classified as joint ventures but which are not consolidated, are reclassified under the Investment group’s Income Statement for groups of costs and income tax and social security contributions.

(In thousands of Reals, unless stated otherwise)

Below is the movement of the Parent Company's investment in 2026 and 2025:

Parent Company
Companies Final balance on 12/31/2025 Capital increase and (Decrease)/acquisition of shares Dividends Equity Income Comprehensive income Final balance on 03/31/2026
Investments under the equity method
Subsidiaries
CSN Steel S.L.U. 4,588,942 (27,753) (211,995) 4,349,194
Sepetiba Tecon S.A. 293,089 (861) (6,138) 286,090
Minérios Nacional  S.A. 67,323 44,600 (31,026) 80,897
Fair Value - Minérios Nacional 2,122,071 2,122,071
Goodwill - Companhia Metalúrgica Prada 63,509 63,509
CSN Mineração S.A. 6,232,504 155,191 169,067 6,556,762
Lucros não realizado CSN Mineração S.A.^^ (2,351,078) (2,351,078)
CSN Energia S.A. 26,240 13,612 39,852
FTL - Ferrovia Transnordestina Logística S.A. 58,759 (16,826) 41,933
Companhia Florestal do Brasil 1,220,610 900 (12,766) 10 1,208,754
CBSI - Companhia Brasileira de Serviços de Infraestrutura 153,611 31,522 185,133
Goodwill - CBSI - Companhia Brasileira de Serviços de Infraestrutura 15,225 15,225
CSN Cimentos Brasil S.A. 6,721,411 6,978 6,728,389
Estrela Comércio e Participações S.A 138,777 (16,959) (14,356) (1,710) 105,752
Ágio - Estrela Comércio e Participações S.A^^ 596,802 (325,569) 271,233
Fair value Grupo Estrela 276,735 (98,316) 178,419
Nordeste Logística S.A. 5,163 1,536 (715) 5,984
CSN Captive Insurance Company LLC 4,631 (63) (243) 4,325
Others 31,722 (1,535) 30,187
19,989,311 (18,757) - 3,086 (51,009) 19,922,631
Joint-venture, Joint-operation and Affiliate
Itá Energética S.A. 178,837 3,642 182,479
MRS Logística S.A. 684,245 (28,014) 5,473 1 661,705
Transnordestina Logística S.A. 2,916,482 1,444 2,917,926
Fair Value -Transnordestina 659,106 659,106
Equibras S.A.^^ 39,054 (632) 38,422
Panatlântica S.A. 219,555 (3,538) 5,934 221,951
Arvedi Metalfer do Brasil S.A. 34,601 34,601
4,731,880 (31,552) 15,861 1 4,716,190
Other participations
Profits on subsidiaries' inventories (20,833) 4,790 (16,043)
Other investments 39 39
(20,794) 4,790 (16,004)
Total shareholdings 24,700,397 (18,757) (31,552) 23,737 (51,008) 24,622,817
Subsidiaries with unsecured liabilities
CSN Islands VII Corp. (3,010,378) 136,717 (2,873,661)
CSN Inova Ventures (3,468,244) 56,635 (3,411,609)
CSN Islands XII Corp. (4,825,169) 135,527 (4,689,642)
Estanho de Rondônia S.A. (63,682) 11,000 (8,634) (61,316)
Companhia Metalúrgica Prada PPI (65,095) (57,902) (122,997)
Others (13,963) (2,169) (16,132)
Total subsidiaries with unsecured liabilities (11,446,531) 11,000 260,174 (11,175,357)
Equity Income 283,911
Classification of investments in the balance sheet
Equity interests 24,700,397 24,622,817
Investment Property 154,801 154,227
Total active investments 24,855,198 24,777,044
Provision for Investments with Unsecured Liabilities (liabilities) (11,446,531) (11,175,357)
Total active and passive investments 13,408,667 13,601,687
---

(In thousands of Reals, unless stated otherwise)

Parent Company
Companies Final balance on 12/31/2024 Capital increase and (Decrease)/acquisition of shares Sales of shares Dividends Equity Income Comprehensive income Final balance on 12/31/2025
Investments under the equity method
Subsidiaries
CSN Steel S.L.U. 4,618,406 (49,420) 19,956 4,588,942
Sepetiba Tecon S.A. 302,152 (9,063) 293,089
Minérios Nacional  S.A. 90,578 113,754 (137,009) 67,323
Fair Value - Minérios Nacional 2,122,071 2,122,071
Companhia Metalúrgica Prada ^(6)^ 181,686 (181,686)
Goodwill - Companhia Metalúrgica Prada 63,509 63,509
CSN Mineração S.A. ^(1)^ 7,086,794 (2,366,259) 1,138,430 373,539 6,232,504
Lucros não realizado CSN Mineração S.A. ^(1)^ (2,351,078) (2,351,078)
CSN Energia S.A. 20,142 6,098 26,240
FTL - Ferrovia Transnordestina Logística S.A. 100,314 (41,555) 58,759
Companhia Florestal do Brasil 1,246,403 2,700 (28,920) 427 1,220,610
CBSI - Companhia Brasileira de Serviços de Infraestrutura 84,226 (21,345) 90,730 153,611
Goodwill - CBSI - Companhia Brasileira de Serviços de Infraestrutura 15,225 15,225
CSN Cimentos Brasil S.A. 6,612,579 (21,441) 132,829 (2,556) 6,721,411
Estrela Comércio e Participações S.A ^(2)^ 155,691 (16,914) 138,777
Ágio - Estrela Comércio e Participações S.A ^(2)^ 596,802 596,802
Nordeste Logística S.A. 8,072 (2,909) 5,163
CSN Captive Insurance Company LLC ^(3)^ 4,550 16 65 4,631
Others 313 31,483 (74) 31,722
22,544,398 913,052 - (2,409,045) (1,450,525) 391,431 19,989,311
Joint-venture, Joint-operation and Affiliate
Itá Energética S.A. 177,351 (8,332) 9,818 178,837
MRS Logística S.A. ^(1)^ 1,400,002 (998,922) 283,182 (17) 684,245
Transnordestina Logística S.A. ^(4)^ 1,137,345 1,792,580 (18,129) 4,686 2,916,482
Fair Value -Transnordestina 659,106 659,106
Equibras S.A. ^(5)^ 31,733 (2,187) 9,508 39,054
Panatlântica S.A. 225,764 (19,477) 13,268 219,555
Arvedi Metalfer do Brasil S.A. 35,257 (656) 34,601
3,666,558 1,792,580 (998,922) (29,996) 296,991 4,669 4,731,880
Other participations
Profits on subsidiaries' inventories (53,731) 32,898 (20,833)
Other investments 39 39
(53,692) 32,898 (20,794)
Total shareholdings 26,157,264 2,705,632 (998,922) (2,439,041) (1,120,636) 396,100 24,700,397
Subsidiaries with unsecured liabilities
CSN Islands VII Corp. (3,255,338) 244,960 (3,010,378)
CSN Inova Ventures (3,348,913) (119,331) (3,468,244)
CSN Islands XII Corp. (4,803,727) (21,442) (4,825,169)
Estanho de Rondônia S.A. (47,190) 64,500 (80,992) (63,682)
Companhia Metalúrgica Prada PPI ^(6)^ (65,095) (65,095)
Others (3,645) 3,032 (13,350) (13,963)
Total subsidiaries with unsecured liabilities (11,458,813) 67,532 (55,250) (11,446,531)
Equity Income (1,175,886)
Classification of investments in the balance sheet
Equity interests 26,157,265 24,700,397
Investment Property 135,557 154,801
Total active investments 26,292,822 24,855,198
Provision for Investments with Unsecured Liabilities (liabilities) (11,458,813) (11,446,531)
Total active and passive investments 14,834,009 13,408,667

(1) In December 2025, CSN sold 59.5% of its equity interest in MRS to its subsidiary CSN Mineração and now holds a 7.59% stake in MRS. As of the same date, its subsidiary CMIN came to hold a 29.91% participation in MRS. This transaction was carried out for the total price of R$ 3,350,000 previously received by CSN, and the book value of MRS's investment was written off in the amount of (R$998,922). Consequently, a gain of R$2,351,078 was recorded under “Other operating income” (Note 27), and as required by CPC 18 and ICPC 09, “Transactions under common control,” it was offset at the Parent Company through the unrealized gain in CSN Mineração. This sale did not represent a realized gain or loss for the CSN Group. Effective economic realization of the investment will only take place once the sale is made outside CSN’s economic group.

(In thousands of Reals, unless stated otherwise)

(2) Transaction related to the acquisition of a stake in Grupo Estrela, entered into on April 1, 2025. According to CPC 15 (R1) – Business combination, the Company has one year, as of the acquisition date, to form the respective business combination, which may impact the recorded fair value within this period based on an appraisal report.

(3) On August 29, 2025, the Company paid in capital in its subsidiary CSN Captive Insurance Company LLC. CSN Captive, which is located in the United States, was incorporated as a limited liability company and its corporate purpose is to operate in the insurance market, providing insurance coverage to companies in which the Company holds an participation, as well as to third parties.

(4) Paying in of AFACs by CSN on October 17, 2025.

(5) Equimac S.A. changed its corporate name in December 2025 to "Equibras S.A.", with no change in the Company's interest in this company.

(6) On December 31, 2025, the subsidiary Prada was transferred to the group of Subsidiaries with unsecured liabilities.

10.b) Joint- Ventures and Joint-Operations Financial Information

Balance sheet and income statement at companies subject to shared control are shown below and refer to 100% of the companies' profit or loss:

03/31/2026 12/31/2025
Joint-Venture Joint-Operation Joint-Venture Joint-Operation
Equity interest (%) MRS Logística ^(1)^ Transnordestina Logística Equibras S.A. Itá Energética MRS Logística Transnordestina Logística Equibras S.A. Itá Energética
37.49% 33.89% 50.00% 48.75% 37.49% 33.89% 50.00% 48.75%
Balance sheet
Current Assets
Cash and cash equivalents 4,706,502 1,217,587 11,044 137,238 4,131,117 1,740,636 16,678 112,820
Advances to suppliers 42,876 145,339 1,089 510 37,512 62,240 34 527
Other assets 1,019,319 98,293 26,485 24,478 1,127,557 92,864 36,254 31,004
Total current assets 5,768,697 1,461,219 38,618 162,226 5,296,186 1,895,740 52,966 144,351
Non-current Assets
Other assets 1,394,992 84,475 243 8,139 1,147,003 88,455 259 9,478
Investments, PP&E and intangible assets 18,638,722 15,674,811 94,875 225,647 18,259,793 15,142,520 79,683 233,519
Total non-current assets 20,033,714 15,759,286 95,118 233,786 19,406,796 15,230,975 79,942 242,997
Total Assets 25,802,411 17,220,505 133,736 396,012 24,702,982 17,126,715 132,908 387,348
Current Liabilities
Borrowings and financing 1,084,299 31,437 22,908 1,013,759 65,418 14,266
Lease liabilities 306,855 328 491,501 337
Other liabilities 1,837,089 338,218 11,285 16,010 1,710,146 176,437 19,979 15,074
Total current liabilities 3,228,243 369,655 34,521 16,010 3,215,406 241,855 34,582 15,074
Non-current Liabilities
Borrowings and financing 9,628,567 7,082,711 19,219 8,572,213 6,877,310 16,447
Lease liabilities 2,578,613 471 2,500,878 333
Other liabilities 1,637,377 1,159,039 2,682 5,686 1,393,766 1,402,711 3,438 5,429
Total non-current liabilities 13,844,557 8,241,750 22,372 5,686 12,466,857 8,280,021 20,218 5,429
Shareholders’ equity 8,729,611 8,609,100 76,843 374,316 9,020,719 8,604,839 78,108 366,845
Total liabilities and shareholders’<br><br>equity 25,802,411 17,220,505 133,736 396,012 24,702,982 17,126,715 132,908 387,348
01/01/2026 to 03/31/2026 01/01/2025 to 03/31/2025
--- --- --- --- --- --- --- --- ---
Joint-Venture Joint-Operation Joint-Venture Joint-Operation
Equity interest (%) MRS Logística Transnordestina Logística Equibras S.A. Itá Energética MRS Logística Transnordestina Logística Equimac S.A. ^(2)^ Itá Energética
37.49% 33.89% 50.00% 48.75% 37.49% 48.03% 50.00% 48.75%
Statements of Income
Net revenue 1,674,556 15,288 49,919 1,676,603 23,101 49,262
Cost of sales and services (951,788) (8,854) (27,507) (969,927) (12,456) (24,230)
Gross profit 722,768 6,434 22,412 706,676 10,645 25,032
Operating (expenses) income (152,774) (12,090) (1,118) (17,841) (105,397) (13,572) (1,639) (18,068)
Financial income (expenses), net (288,671) 16,485 (897) 6,757 (197,871) (1,693) (1,250) 1,760
Profit/(Loss) before IR/CSLL 281,323 4,395 4,419 11,328 403,408 (15,265) 7,756 8,724
Current and deferred IR/CSLL (203,114) (135) (1,038) (3,856) (120,691) (1,497) (2,167)
Profit / (loss) for the period 78,209 4,260 3,381 7,472 282,717 (15,265) 6,259 6,557

(1) CSN holds a direct 7.59% stake and an indirect 29.91% stake through CSN Mineração in MRS’s total share capital, for a combined total of 37.49%. The CSN Group was assigned a total interest of 28.23% after the participation of the non-controlling shareholders.

(In thousands of Reals, unless stated otherwise)

(2) Equimac S.A. changed its corporate name in December 2025 to "Equibras S.A.", with no change in the Company's interest in this company.

10.c) Investment Properties

The balance of investment properties is shown below:

Consolidated Parent Company
Ref. Land Buildings Total Land Buildings Total
Balance at December 31, 2024 156,858 45,182 202,040 94,257 41,300 135,557
Depreciation (3,916) (3,916) (2,157) (2,157)
Acquisitions 21,401 21,401 21,401 21,401
Balance at December 31, 2025 178,259 41,266 219,525 115,658 39,143 154,801
Cost 178,259 83,285 261,544 115,658 74,389 190,047
Accumulated depreciation (42,019) (42,019) (35,246) (35,246)
Balance at December 31, 2025 178,259 41,266 219,525 115,658 39,143 154,801
Depreciation 26 (977) (977) (538) (538)
Transfer between groups - fixed assets and investment property (36) (36) (36) (36)
Balance at March 31, 2026 178,259 40,253 218,512 115,658 38,569 154,227
Cost 178,259 83,183 261,442 115,658 74,288 189,946
Accumulated depreciation (42,930) (42,930) (35,719) (35,719)
Balance at March 31, 2026 178,259 40,253 218,512 115,658 38,569 154,227

The Company Management's estimate of the fair value of investment properties was carried out for December 31, 2025. The fair value of investment property in the consolidated financial statements as of March 31, 2026, is R$3,818,752 (R$3,818,752 as of December 31, 2025) and R$3,337,307 for the parent company (R$3,337,307 as of December 31, 2025).

The estimated average useful lives for the periods are as follows (in years):

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Buildings 28 28 30 30
---

(In thousands of Reals, unless stated otherwise)

11. PROPERTY, PLANT AND EQUIPMENT
11.a) Composition of property, plant and equipme nt

Breakdown of Consolidated fixed assets as of March 31, 2026 and December 31, 2025, respectively:

Consolidated
Ref. Land Buildings and Infrastructure Machinery, equipment and facilities Vehicles Construction in progress (*) Right of use Other (**) Total
Balance at December 31, 2024 592,716 4,772,512 17,969,066 208,941 5,881,336 756,814 244,638 30,426,023
Effect of foreign exchange differences 8,772 (1,184) (5,886) (23) 14,549 (4,027) (6,447) 5,754
Acquisitions 11,171 36,813 379,302 193,804 5,296,362 72,305 15,468 6,005,225
Capitalized interest 28 403,302 403,302
Write-offs 27 (6,141) (69,999) (803) (14,714) (10,707) (116) (102,480)
Depreciation 26 (347,648) (3,184,112) (100,773) (283,840) (39,781) (3,956,155)
Transfers to other asset categories 6,952 274,578 3,308,081 33,119 (3,589,738) (32,992)
Transfer between groups - intangible assets, investment and property and inventory ^(1)^ - (34,100) (34,122) (45,190) (113,412)
Acquisition of stakes in subsidiaries 9,414 144,879 94,773 536,671 1,550 183,929 47,256 1,018,472
Right of use - Remeasurement 244,543 244,543
Others (207) (9,936) (1,961) (12,104)
Balance at December 31, 2025 629,025 4,873,809 18,456,918 826,879 7,947,457 959,016 226,065 33,919,169
Cost 629,025 10,287,766 43,130,128 1,536,918 7,947,457 1,711,164 771,928 66,014,386
Accumulated depreciation (5,413,957) (24,673,210) (710,039) (752,148) (545,863) (32,095,217)
Balance at December 31, 2025 629,025 4,873,809 18,456,918 826,879 7,947,457 959,016 226,065 33,919,169
Effect of foreign exchange differences (8,440) (17,879) (41,275) (114) (7,010) (4,709) (3,163) (82,590)
Acquisitions 140 28 59,428 17,982 1,036,855 21,890 1,093 1,137,416
Capitalized interest 28 131,770 131,770
Write-offs 27 (614) (356) (1,046) (8) (2,024)
Depreciation 26 (85,388) (800,980) (103,198) (81,882) (10,304) (1,081,752)
Transfers to other asset categories (3) 64,776 483,482 19,646 (612,013) 44,112
Transfer between groups - intangible assets, investment property and inventory ^(1)^ 36 216 114,112 (20,654) 93,710
Right of use - Remeasurement 4,006 4,006
Others 10,643 (3,738) 6,392 13,297
Balance at March 31, 2026 620,722 4,835,382 18,167,818 871,212 8,476,405 897,275 264,187 34,133,001
Cost 620,722 10,304,780 43,810,188 1,690,298 8,476,405 1,714,765 756,789 67,373,947
Accumulated depreciation (5,469,398) (25,642,370) (819,086) (817,490) (492,602) (33,240,946)
Balance at March 31, 2026 620,722 4,835,382 18,167,818 871,212 8,476,405 897,275 264,187 34,133,001

(*) Progress is highlighted in the projects of: (i) business expansion, mainly expansion of the port in Itaguaí and Casa de Pedra, Itabirito project and recovery of tailings from dams; (ii) projects of new integrated cement plants (iii); general repair of the blast furnace and coke batteries at the Presidente Vargas Plant; and (iv) added to the interest capitalized in the period.

(**) Refer substantially to assets classified as furniture, utensils and hardware.

(1) Transfer to stock refers to the allocation of decommissioned or replaced vehicle assets. These assets are subsequently made available for sale by the companies Tora Seminovos Comércio de Veículos Ltda and Seminovos Lokamig Ltda, in line with the company's main commercial activities, which is the resale of used vehicles.

(In thousands of Reals, unless stated otherwise)

Composition of the Parent Company's fixed assets as of March 31, 2026 and December 2025, respectively:

Parent Company
Ref. Land Buildings and Infrastructure Machinery, equipment and facilities Vehicles Construction in progress (*) Right of use Others (**) Total
Balance at December 31, 2024 25,618 328,915 7,229,728 24,209 1,984,214 37,582 34,147 9,664,413
Acquisitions 173,392 1,034 2,090,139 449 2,265,014
Capitalized interest 28 210,732 210,732
Write-offs 27 (1,717) - (1,717)
Depreciation 26 (31,442) (1,341,793) (6,695) (10,671) (8,977) (1,399,578)
Transfers to other asset categories 88,482 1,719,264 403 (1,820,944) 12,795
Transfers to intangible assets (17,325) (17,325)
Right of use - Remeasurement 8,238 8,238
Others (207) - (207)
Balance at December 31, 2025 25,618 385,955 7,778,667 18,951 2,446,816 35,149 38,414 10,729,570
Cost 25,618 703,043 17,452,010 67,287 2,446,816 51,024 230,239 20,976,037
Accumulated depreciation (317,088) (9,673,343) (48,336) (15,875) (191,825) (10,246,467)
Balance at December 31, 2025 25,618 385,955 7,778,667 18,951 2,446,816 35,149 38,414 10,729,570
Acquisitions 41,211 364,577 1,041 406,829
Capitalized interest 28 61,355 61,355
Write-offs 27 (308) (38,914) (39,222)
Depreciation 26 (8,246) (311,717) (1,470) (2,684) (2,143) (326,260)
Transfers to other asset categories (3) 9,725 109,726 (122,581) 3,133
Transfers to intangible assets 35 (14,249) (14,214)
Balance at March 31, 2026 25,615 387,469 7,617,579 17,481 2,697,004 33,506 39,404 10,818,058
Cost 25,615 712,869 17,888,959 67,287 2,697,004 52,064 233,373 21,677,171
Accumulated depreciation (325,400) (10,271,380) (49,806) (18,558) (193,969) (10,859,113)
Balance at March 31, 2026 25,615 387,469 7,617,579 17,481 2,697,004 33,506 39,404 10,818,058

(*) (i) General repair of the blast furnace and coke batteries at the Presidente Vargas Plant; and, (ii) added to the interest capitalized in the period.

(**) Refer substantially to assets classified as furniture, utensils and hardware.

The estimated average useful lives are as follows (in years):

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Buildings and Infrastructure 32 32 27 27
Machinery, equipment and facilities 17 17 18 18
Vehicles 11 10 11 11
Others 11 10 9 9
---

(In thousands of Reals, unless stated otherwise)

11.b) Right of Use

Below are the movements of the right of use:

Consolidated
Land Buildings and Infrastructure Machinery, equipment and facilities Vehicles Total
Balance at December 31, 2024 537,008 83,112 114,612 22,082 756,814
Effect of foreign exchange differences (4,622) 758 (163) (4,027)
Acquisition of stakes in subsidiaries 183,929 - - 183,929
Addition 5,906 1,826 61,968 2,605 72,305
Remeasurement 63,305 1,715 138,824 40,699 244,543
Depreciation (63,113) (17,914) (175,799) (27,014) (283,840)
Write-offs (680) (10,028) (10,708)
Balance at December 31, 2025 726,355 64,117 130,335 38,209 959,016
Cost 996,234 143,181 431,606 140,143 1,711,164
Accumulated depreciation (269,879) (79,064) (301,271) (101,934) (752,148)
Balance at December 31, 2025 726,355 64,117 130,335 38,209 959,016
Effect of foreign exchange differences (1,733) (1,103) (1,872) (4,708)
Acquisition of stakes in subsidiaries 20,636 1,253 21,889
Remeasurement (25,952) 8 29,763 186 4,005
Depreciation (17,266) (4,381) (58,522) (1,713) (81,882)
Write-offs (570) (475) (1,045)
Transfers to other asset categories 2,391 (1,825) (566)
Balance at March 31, 2026 684,958 56,186 121,109 35,022 897,275
Cost 971,100 135,971 473,698 133,996 1,714,765
Accumulated depreciation (286,142) (79,785) (352,589) (98,974) (817,490)
Balance at March 31, 2026 684,958 56,186 121,109 35,022 897,275
Parent Company
--- --- --- --- ---
Land Machinery, equipment and facilities Vehicles Total
Balance at December 31, 2024 37,394 188 - 37,582
Remeasurement 7,068 669 501 8,238
Depreciation (9,332) (842) (497) (10,671)
Balance at December 31, 2025 35,130 15 4 35,149
Cost 47,980 851 2,193 51,024
Accumulated depreciation (12,850) (836) (2,189) (15,875)
Balance at December 31, 2025 35,130 15 4 35,149
Addition 1,041 1,041
Depreciation (2,414) (9) (261) (2,684)
Balance at March 31, 2026 32,716 6 784 33,506
Cost 47,980 851 3,233 52,064
Accumulated depreciation (15,264) (845) (2,449) (18,558)
Balance at March 31, 2026 32,716 6 784 33,506
---

(In thousands of Reals, unless stated otherwise)

12. INTANGIBLE ASSETS

Conposition of Consolidated’s intangible assets as March 31, 2026 and December 2025, respectively:

Consolidated Parent Company
Ref. Goodwill Customer relationships Software Trademarks<br><br>and<br><br>patents Rights and licenses<br><br>(*) Others Total Software Total
Balance at December 31, 2024 4,126,255 40,239 114,000 252,428 5,902,886 2,283 10,438,091 68,070 68,070
Effect of foreign exchange differences 15 37 734 262 1,048
Acquisitions 2,977 2,977
Transfer between groups - fixed assets 45,190 - 45,190 17,325 17,325
Amortization (9,669) (36,325) (17) (144,393) (190,404) (19,439) (19,439)
Transfers to other asset categories (13,715) 21,300 339 (5,652) (2,272)
Acquisition of stakes in subsidiaries 653,074 8,247 1,044 45,280 - 707,645
Others 1,578 1,578
Balance at December 31, 2025 4,779,329 25,117 148,223 298,764 5,754,681 11 11,006,125 65,956 65,956
Cost 5,328,376 881,322 436,871 302,347 6,383,219 11 13,332,146 235,165 235,165
Accumulated amortization (549,047) (856,205) (288,648) (3,583) (628,538) (2,326,021) (169,209) (169,209)
Balance at December 31, 2025 4,779,329 25,117 148,223 298,764 5,754,681 11 11,006,125 65,956 65,956
Effect of foreign exchange differences (522) (15,459) (2,339) (18,320)
Acquisitions 1,198 8,870 10,068
Transfer between groups - fixed assets (161) 20,654 802 52,366 73,661 14,249 14,249
Write-offs 27
Amortization 26 (27,194) (9,754) (1,621) (33,858) (72,427) (5,055) (5,055)
Transfers to other asset categories (3,435) (349) 3,784
Goodwill - Estrela Comércio e Participações S.A (352,209) 295,853 9,844 (46,512)
Others 3,435 (492) 2,943
Balance at March 31, 2026 4,427,120 290,180 162,885 292,330 5,724,115 58,908 10,955,538 75,150 75,150
Cost 4,976,167 1,117,909 463,939 297,534 6,382,727 58,908 13,297,184 252,096 252,096
Accumulated amortization (549,047) (827,729) (301,054) (5,204) (658,612) (2,341,646) (176,946) (176,946)
Balance at March 31, 2026 4,427,120 290,180 162,885 292,330 5,724,115 58,908 10,955,538 75,150 75,150

(*) Composed mainly of: (i) mining rights amortized by production volume and (ii) Concession contract for hydroelectric resource utilization in acquiring control of Companhia Estadual de Geração de Energia Elétrica, CEEE-G, with amortization performed over the contract's term.

The estimated average useful lives are as follows (in years):

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Software 8 8 8 8
Customer relationships 13 13
---

(In thousands of Reals, unless stated otherwise)

13. BORROWINGS AND FINANCING

The balances of loans, financing and bonds that are recorded at amortized cost are as follows:

Consolidated Parent Company
Current Liabilities Non-current Liabilities Current Liabilities Non-current Liabilities
03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Foreign Debt
Floating Rates:
Prepayment 1,847,566 3,236,980 5,906,416 5,601,328 359,940 1,639,533 1,524,065 1,331,581
Fixed Rates:
Bonds, Facility and ACC 3,895,455 4,034,971 19,064,173 20,152,704 2,224,897 2,437,801 1,291,802 1,332,774
Intercompany 231,928 193,334 8,714,528 9,454,192
Fixed interest in
Facility 667,224 637,083 293,290 234,411
Intercompany 5,642 320 328,457 353,480
6,410,245 7,909,034 25,263,879 25,988,443 2,822,407 4,270,988 11,858,852 12,472,027
Debt agreements in R
Floating Rate Securities
BNDES/FINAME/FINEP, Debentures, CRI and NCE 2,756,024 2,613,940 16,648,082 17,081,203 2,159,143 1,944,326 8,592,066 8,920,480
2,756,024 2,613,940 16,648,082 17,081,203 2,159,143 1,944,326 8,592,066 8,920,480
Total Borrowings and Financing 9,166,269 10,522,974 41,911,961 43,069,646 4,981,550 6,215,314 20,450,918 21,392,507
Transaction Costs and Issue Premiums (90,714) (94,415) (552,387) (573,658) (23,766) (24,550) (101,085) (106,851)
Total Borrowings and Financing + Transaction cost 9,075,555 10,428,559 41,359,574 42,495,988 4,957,784 6,190,764 20,349,833 21,285,656

All values are in Euros.

13.a) Changes in Borrowings and Financing

The following table shows the reconciliation of the book value at the beginning and end of the period:

Consolidated Parent Company
Ref. 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Opening balance 52,924,548 56,914,621 27,476,421 30,245,640
New debts 1,859,743 11,121,708 414,296 2,558,006
Repayment (2,793,057) (11,717,772) (1,949,650) (3,434,578)
Payments of charges (878,933) (4,267,926) (352,651) (1,910,666)
Accrued charges 28 1,060,051 4,314,121 469,160 1,987,311
Acquisition of stakes in subsidiaries 641,574
Iron ore prepayment ^(1)^ 66,717
Amortization of iron ore prepayments ^(1)^ (66,717)
Other ^(2)^ (1,737,223) (4,081,779) (749,959) (1,969,293)
Closing balance 50,435,129 52,924,547 25,307,617 27,476,420

(1) They refer to iron ore prepayment bonds that were initially recognized as contract liabilities, as they refer to a future obligation to deliver the product. However, given the impossibility of delivering the product during the period and the need for a cash settlement, this obligation came to be characterized as a monetary item and was reclassified as financial liability. These amounts were fully settled for the period.

(2) Amounts include unrealized changes in exchange rate and inflation, as well as costs of capital raising.

(In thousands of Reals, unless stated otherwise)

The Company raised and amortized debts during 2026, as shown below:

Consolidated
03/31/2026
Nature New debts Maturities Repayment Interest payment
Pre-Payment 699,635 2027 (1,271,183) (238,965)
Bonds, Foreign Exchange Contract and Facility 1,140,753 2026 to 2032 (1,039,407) (402,006)
BNDES/FINAME/FINEP, Debentures, CRI and NCE 19,355 2026 to 2032 (482,467) (237,962)
1,859,743 (2,793,057) (878,933)
Parent Company
03/31/2026
Nature New debts Maturities Repayment Interest payment
Pre-Payment (851,764) (174,046)
Bonds and ACC 414,296 2026 to 2032 (715,842) (177,737)
BNDES/FINAME/FINEP, Debentures, CRI and NCE (149,006) (868)
Intercompany (233,038)
414,296 (1,949,650) (352,651)
13.b) Maturities of Debts Presented in Current and Non-Current Liabilities
Consolidated Parent Company
03/31/2026 03/31/2026
In foreign currency In national currency - R$ Total In foreign currency In national currency - R$ Total
Average rate US$<br> 6.41% €  3.41% R 16.40% US$<br> 3.66% € 5.56% R 16.81%
2026 5,498,223 2,102,873 7,601,096 2,404,855 1,590,699 3,995,554
2027 4,446,985 3,983,158 8,430,143 1,851,885 3,281,629 5,133,514
2028 9,315,423 2,433,064 11,748,487 3,430,469 1,779,978 5,210,447
2029 473,708 1,820,988 2,294,696 1,099,347 902,251 2,001,598
2030 4,079,546 1,723,919 5,803,465 2,822,531 860,671 3,683,202
2031 4,858,667 1,542,236 6,400,903 458,783 255,995 714,778
After 2031 3,001,572 5,797,868 8,799,440 2,613,389 2,079,986 4,693,375
31,674,124 19,404,106 51,078,230 14,681,259 10,751,209 25,432,468

All values are in US Dollars.

Consolidated Parent Company
12/31/2025 12/31/2025
In foreign currency In national currency - R$ Total In foreign currency In national currency - R$ Total
Average rate US$<br>6.42%  € 3.53% R 16.1% US$<br>3.80%   €<br>3.53% R 17.05%
2026 7,909,035 2,613,938 10,522,973 4,270,989 1,944,325 6,215,314
2027 3,890,494 3,915,457 7,805,951 1,512,104 3,252,053 4,764,157
2028 8,891,443 2,509,911 11,401,354 3,553,699 1,860,022 5,413,721
2029 564,742 1,909,546 2,474,288 1,183,036 982,295 2,165,331
2030 4,319,384 1,632,412 5,951,796 2,967,600 761,299 3,728,899
2031 5,144,744 1,460,420 6,605,164 483,658 151,259 634,917
After 2031 3,177,635 5,653,459 8,831,094 2,771,929 1,913,553 4,685,482
33,897,477 19,695,143 53,592,620 16,743,015 10,864,806 27,607,821

All values are in US Dollars.

(In thousands of Reals, unless stated otherwise)

·   Covenants

The Company's debt contracts provide for compliance with certain non-financial obligations, as well as maintenance of specific performance parameters and indicators, such as the disclosure of audited financial statements according to regulatory deadlines or having early maturity declared if the net debt to EBITDA indicator reaches the levels specified in these contracts.

As of the present date, the Company is compliant with the financial and non-financial obligations (covenants) of its current contracts.

14. FINANCIAL INSTRUMENTS
14.a) Identification and Valuation of Financial Instruments

The Company may operate with several financial instruments, with an emphasis on cash and cash equivalents, including investments, marketable securities, accounts receivables from customers, accounts payables to suppliers and borrowings and financing. Additionally, the Company may also operate with financial derivatives, such as swap of exchange or interest and commodities and exchange derivatives.

Given the nature of these instruments, fair value is essentially determined through the use of observable quotations in active markets, particularly B3 S.A. – Brasil, Bolsa, Balcão. The amounts recorded in current assets and liabilities have immediate liquidity or maturity, mostly in the short term. Considering the terms and characteristics of these instruments, the carrying amounts approximate the fair values.

(In thousands of Reals, unless stated otherwise)

Classification of financial instruments

Consolidated
03/31/2026 12/31/2025
Ref. Fair value through other comprehensive income Fair value through profit or loss Measured at amortized cost Balances Fair value through other comprehensive income Fair value through profit or loss Measured at amortized cost Balances
Assets
Current
Cash and cash equivalents 4 12,822,834 12,822,834 14,421,022 14,421,022
Financial investments 5 418,628 198,083 616,711 372,397 270,318 642,715
Trade receivables 6 71,236 2,826,640 2,897,876 66,464 2,330,569 2,397,033
Dividends and interest on equity 9 217,746 217,746 76,026 76,026
Derivative financial instruments 9 4,080 3,375 7,455 494 494
Receivables - Usiminas Shares 9 204,852 204,852 192,911 192,911
Other receivables 2,377 2,377
Trading securities 9 3,079 3,079 2,598 2,598
Loans - related parties 9 2,944 2,944 4,147 4,147
Total 4,080 496,318 16,273,099 16,773,497 - 441,953 17,297,370 17,739,323
Non-current
Financial investments 5 25,867 25,867 25,257 25,257
Receivables - Usiminas Shares 9 150,578 150,578 150,578 150,578
Other trade receivables 22,785 22,785 19,759 19,759
Eletrobrás compulsory loan 9 3,787 3,787
Receivables by indemnity 9 840,536 840,536 779,827 779,827
Loans - related parties 9 1,663,922 1,663,922 2,137,882 2,137,882
Total 2,703,688 2,703,688 - 3,117,090 3,117,090
Total Assets 4,080 496,318 18,976,787 19,477,185 - 441,953 20,414,460 20,856,413
Liabilities
Current
Borrowings and financing 13 9,166,269 9,166,269 10,522,974 10,522,974
Lease liabilities 15 212,434 212,434 238,702 238,702
Trade payables 16 6,531,907 6,531,907 7,162,929 7,162,929
Trade payables - Forfaiting 16.a 2,410,807 2,410,807 2,905,018 2,905,018
Dividends and interest on capital 18 1,140,000 1,140,000 358,040 358,040
Derivative transactions 18 1,731 1,731 67,304 67,304
Concessions to be paid 18 13,336 13,336 13,350 13,350
Total 1,731 19,474,753 19,476,484 67,304 21,201,013 21,268,317
Non-current
Borrowings and financing 13 41,911,961 41,911,961 43,069,646 43,069,646
Lease liabilities 15 839,137 839,137 855,037 855,037
Trade payables 16 68,555 68,555 66,807 66,807
Derivative transactions 18 141,085 141,085 153,507 153,507
Concessions to be paid 18 77,771 77,771 78,419 78,419
Contractual liability arising from a stock option 298,662 298,662
Total 298,662 141,085 42,897,424 43,337,171 - 153,507 44,069,909 44,223,416
Total Liabilities 298,662 142,816 62,372,177 62,813,655 67,304 153,507 65,270,922 65,491,733
---

(In thousands of Reals, unless stated otherwise)

Parent Company
03/31/2026 12/31/2025
Ref. Fair value through other comprehensive income Fair value through profit or loss Measured at amortized cost Balances Fair value through profit or loss Measured at amortized cost Balances
Assets
Current
Cash and cash equivalents 4 1,785,070 1,785,070 3,529,453 3,529,453
Financial investments 5 418,628 8,878 427,506 372,397 8,577 380,974
Trade receivables 6 2,101,001 2,101,001 1,702,245 1,702,245
Dividends and interest on equity 9 400,443 400,443 1,167,342 1,167,342
Derivative financial instruments 9 3,375 3,375
Receivables - Usiminas Shares 9 204,852 204,852 192,910 192,910
Trading securities 9 2,876 2,876 2,408 2,408
Loans - related parties 9 2,944 2,944 4,147 4,147
Total - 424,879 4,503,188 4,928,067 374,805 6,604,674 6,979,479
Non-current
Receivables - Usiminas Shares 9 150,578 150,578 150,578 150,578
Other trade receivables 1,115 1,115 1,115 1,115
Eletrobrás compulsory loan 9 678 678
Receivables by indemnity 9 840,536 840,536 779,827 779,827
Loans - related parties 9 3,084,540 3,084,540 3,474,387 3,474,387
Total 4,076,769 4,076,769 4,406,585 4,406,585
Total Assets 424,879 8,579,957 9,004,836 374,805 11,011,259 11,386,064
Liabilities
Current
Borrowings and financing 13 4,981,550 4,981,550 6,215,314 6,215,314
Lease liabilities 15 12,307 12,307 11,525 11,525
Trade payables 16 4,321,780 4,321,780 3,941,596 3,941,596
Trade payables - Forfaiting 16.a 1,606,945 1,606,945 1,924,285 1,924,285
Dividends and interest on capital 18 6,047 6,047 6,059 6,059
Total 10,928,629 10,928,629 12,098,779 12,098,779
Non-current
Borrowings and financing 13 20,450,918 20,450,918 21,392,507 21,392,507
Lease liabilities 15 23,377 23,377 25,570 25,570
Trade payables 16 2,984 2,984 3,328 3,328
Derivative transactions 18 84,896 84,896 117,120 117,120
Contractual liability arising from a stock option ^(1)^ 298,662 298,662
Total 298,662 84,896 20,477,279 20,860,837 117,120 21,421,405 21,538,525
Total Liabilities 298,662 84,896 31,405,908 31,789,466 117,120 33,520,184 33,637,304

(1) Call and put options related to the remaining interest of 30% of the non-controlling shareholders in the Estrela Group, according to Note 18.

Instrument classified at fair value through other comprehensive income ("VJORA"), with recognition in shareholders' equity, in other reserves**.**

(In thousands of Reals, unless stated otherwise)

Fair Value Measurement

The table below shows the financial instruments recorded at fair value through profit or loss, classifying them according to the fair value hierarchy:

Consolidated 03/31/2026 12/31/2025
Level 1 Level 2 Level 3 Balances Level 1 Level 2 Balances
Assets
Current
Financial investments 418,628 418,628 372,397 372,397
Trade receivables, net 71,236 71,236 66,464 66,464
Derivative transactions 7,455 7,455 494 494
Trading securities 3,079 3,079 2,598 2,598
Total Assets 492,943 7,455 500,398 441,459 494 441,953
Liabilities
Current
Derivative financial instruments 1,731 1,731 67,304 67,304
Non-current
Derivative financial instruments 141,085 141,085 153,507 153,507
Contractual liability arising from a stock option 298,662 298,662
Total Liabilities 1,731 141,085 298,662 441,478 220,811 220,811

Level 1 – The data are prices quoted in an active market for identical items to the assets and liabilities being measured.

Level 2 – Considers observable inputs in the market, such as interest rates, foreign exchange, etc., but are not prices traded in active markets.

Level 3 - Uses significant assumptions not observable in the market, with no prices quoted in active markets or sufficient observable data for the direct pricing of these instruments.

14.b) Financial Risk Management

The Company uses risk management strategies, with guidance on the risks incurred on the business.

The nature and general position of financial risks are regularly monitored and managed to assess results and the financial impact on cash flow. Credit limits and the hedge quality of counterparties are also periodically reviewed.

Market risks are hedged when considered necessary to support the corporate strategy or when it is necessary to maintain the level of financial flexibility.

The Company is exposed to exchange rate, interest rate risk, market price, and credit and liquidity risk.

The Company may manage some of the risks using derivative instruments not associated with any speculative trading or short selling.

(In thousands of Reals, unless stated otherwise)

i) Exchange Rate Risk

The exposure arises mainly from the existence of assets and liabilities denominated in dollars, since the Company's functional currency is substantially the Real and is called natural foreign exchange exposure. The net exposure is the result of the offsetting the natural exchange exposure by the instruments of hedge adopted by the Company.

The consolidated net exposure is shown below:

03/31/2026 12/31/2025
Foreign Exchange Exposure (Amounts in US$’000) (Amounts in US$’000)
Cash and cash equivalents overseas 877,673 895,337
Trade receivables 183,844 212,372
Financial investments 455,848 388,705
Borrowings and financing (5,845,455) (6,002,208)
Trade payables (235,647) (248,790)
Others (27,638) (14,528)
Natural Gross Foreign Exchange Exposure (assets - liabilities) (4,591,375) (4,769,112)
Derivative transactions ^(*)^ 4,079,637 4,396,413
Net foreign exchange exposure (511,738) (372,699)

(*) Total notional value of derivative and non-derivative financial instruments used for exchange risk management.

The Company uses Hedge Accounting as a strategy, as well as derivative financial instruments to protect future cash flows.

Sensitivity analysisof Derivative Financial Instruments and Consolidated Foreign Exchange Exposure

The Company evaluated two different scenarios for the analysis of the exchange rate impact: Scenario 1 projects a horizon of increased currency volatility, and Scenario 2 predicts a horizon of currency appreciation. The calculation was based on the closing exchange rate on March 31, 2026, using assumptions based on a dispersion calculation that considers both historical variations in exchange rates and projections developed by management.

The currencies used in the sensitivity analysis and their respective scenarios are shown below:

03/31/2026 12/31/2025
Currency Exchange rate Probable scenario Scenario 1 Scenario 2 Exchange rate Probable scenario Scenario 1 Scenario 2
USD 5.2194 4.9806 5.6493 4.9398 5.5024 5.2006 5.7964 5.0436
---

(In thousands of Reals, unless stated otherwise)

The effects on the result, considering scenarios 1 and 2, are shown below:

03/31/2026
Instruments Notional amount Risk Probable scenario (*)<br><br>R$ Scenario 1 R$ Scenario 2 R$
Cash and cash equivalents overseas 877,673 Dollar (209,588) 377,312 (245,397)
Trade receivables 183,844 Dollar (43,902) 79,035 (51,403)
Financial investments 455,848 Dollar (108,857) 195,969 (127,455)
Borrowings and financing (5,845,455) Dollar 1,395,895 (2,512,961) 1,634,389
Trade payables (235,647) Dollar 56,273 (101,305) 65,887
Others (27,638) Dollar 6,600 (11,882) 7,728
Derivative financial instruments 4,079,637 Dollar (974,217) 1,753,836 (1,140,667)
Impact on profit or loss 122,204 (219,996) 143,082

(*) The probable scenarios were calculated considering the following variations for the risks: Real x Dollar - Valuation of the Real by 4.58%. Source: Central Bank of Brazil on April 14, 2026.

12/31/2025
Instruments Notional amount Risk Probable scenario (*)<br><br>R$ Scenario 1 R$ Scenario 2 R$
Cash and cash equivalents overseas 895,337 Dollar (270,213) 263,229 (410,781)
Trade receivables 212,372 Dollar (64,094) 62,437 (97,436)
Financial investments 388,705 Dollar (117,311) 114,279 (178,338)
Borrowings and financing (6,002,208) Dollar 1,811,466 (1,764,649) 2,753,813
Trade payables (248,790) Dollar 75,085 (73,144) 114,145
Others (14,528) Dollar 4,385 (4,271) 6,665
Derivative financial instruments 4,396,413 Dollar (1,326,838) 1,292,545 (2,017,074)
Impact on profit or loss 112,480 (109,574) 170,994

(*) The probable scenarios were calculated considering the following variations for the risks: Real x Dollar - Valuation of the real by 5.48%. Source: Central Bank of Brazil on February 20, 2026.

ii) Interest Rate Risk

This risk arises from short-term and long-term investments, loans and financing and debentures linked to pre-fixed and post-fixed CDI, TJLP, and SOFR interest rates, which expose these financial assets and liabilities to interest rate fluctuations as shown in the sensitivity analysis table.

Sensitivity Analysis of Interest Rate Changes

Below, we present the sensitivity analysis for risks related to interest rates. The Company considered two different scenarios to assess the impact of variations in these rates: Scenario 1 predicts a horizon of rising interest rates, and Scenario 2 projects a reduction horizon. To carry out the calculation, the closing rates on March 31, 2026 were considered as references, based on a dispersion model, which considers not only the historical variations in interest rates, but also detailed projections by the management.

This approach allows for a comprehensive and precise assessment of potential economic impacts arising from interest rate fluctuations.

(In thousands of Reals, unless stated otherwise)

Consolidated Consolidated
03/31/2026 12/31/2025
Interest Probable scenario Scenario 1 Scenario 2 Probable scenario Scenario 1 Scenario 2
CDI 14.65% 14.96% 12.89% 14.90% 17.69% 12.97%
TJLP 9.19% 9.27% 8.08% 9.07% 9.22% 6.18%
IPCA 3.81% 4.38% 3.33% 4.26% 4.76% 3.96%
SOFR 6M 3.70% 4.25% 3.62% 3.57% 4.70% 3.26%
SOFR 3.68% 5.73% 3.64% 3.87% 5.54% 3.64%
EURIBOR 3M 2.08% 4.33% 2.01% 2.03% 4.31% 1.95%
EURIBOR 6M 2.48% 4.16% 2.09% 2.11% 4.38% 2.02%

The effects on balances in reals related to assets and liabilities linked to interest rates, considering scenarios 1 and 2, are demonstrated below:

Impact on balances on 03/31/2026
Changes in interest rates % p.a Assets Liabilities Probable scenario (*) Scenario 1 Scenario 2
CDI 14.65% 4,294,851 (16,516,926) (1,790,534) (1,828,728) (1,574,823)
TJLP 9.19% (837,564) (76,972) (77,604) (67,661)
IPCA 3.81% (1,333,282) (50,798) (58,371) (44,382)
SOFR 6M 3.70% (3,332,648) (123,309) (141,652) (120,779)
SOFR 3.68% (481,668) (17,725) (27,599) (17,518)
EURIBOR 3M 2.08% (850,115) (17,682) (36,779) (17,057)
EURIBOR 6M 2.48% (110,315) (2,736) (4,584) (2,308)
Impact on profit or loss (2,079,756) (2,175,317) (1,844,528)

(*) The sensitivity analysis is based on the assumption of maintaining as a probable scenario the market values on March 31, 2026 recorded in the Company's assets and liabilities.

Impact on balances on 12/31/2025
Changes in interest rates % p.a Assets Liabilities Probable scenario (*) Scenario 1 Scenario 2
CDI 14.90% 5,509,312 (16,397,776) (1,622,381) (1,926,578) (1,412,668)
TJLP 9.07% (824,228) (74,757) (75,994) (50,901)
IPCA 4.26% (1,286,852) (54,820) (61,224) (50,899)
SOFR 6M 3.57% (5,059,304) (180,829) (237,992) (165,118)
SOFR 3.87% (472,461) (18,284) (26,170) (17,192)
EURIBOR 3M 2.03% (849,153) (17,255) (36,571) (16,517)
EURIBOR 6M 2.11% (22,592) (476) (989) (456)
Impact on profit or loss (1,968,802) (2,365,518) (1,713,751)

(*) Sensitivity analysis is based on the assumption of maintaining market values as of December 31, 2025 recorded in the Company's assets and liabilities as a probable scenario.

iii) Market price risk

The Company is also exposed to market risks related to the volatility of commodity and input prices. In line with its risk management policy, risk mitigation strategies involving commodities may be used to reduce cash flow volatility. These mitigation strategies may incorporate derivative instruments, predominantly forward, futures, and options transactions.

(In thousands of Reals, unless stated otherwise)

Below are the price risk protection instruments, as shown in the following topics:

a) Cash flow Hedge Accounting– “Platts” Index

To better reflect the accounting effects of the "Platts" hedge strategy on the result, the subsidiary CSN Mineração opted to formally designate the hedge and, consequently, adopted hedge accounting for the iron ore derivative as a hedge accounting instrument for its highly probable future iron ore sales. As a result, the mark-to-market arising from the "Platts" volatility will be temporarily recorded in equity and will be taken to the income statement when the sales occur according to the contracted evaluation period. This allows the recognition of "Platts" volatility on iron ore sales to be recognized at the same time.

The Company has periodically reviewed market scenarios to assess its exposure to iron ore price risk to ensure adequate coverage of market price fluctuations. This process involves monitoring fluctuations and trends in global prices, in addition to considering economic and geopolitical factors that may impact the value of this commodity.

The table below shows the result of the derivative instrument up to March 31, 2026:

03/31/2026 03/31/2026 03/31/2025 03/31/2026 03/31/2025 03/31/2026 03/31/2025
Appreciation (R) Fair value (market) Other operating income expenses Other comprehensive income Financial income and expenses (note 28)
Maturity Notional Asset position Liability position Amounts receivable / (payable)
01/01/2026 to 12/31/2025 (Settled) Platts 40,578 31,019 199
01/01/2026 to 01/31/2026 (Settled) Platts (20,853) (538)
02/01/2026 to 02/28/2026 (Settled) Platts 47,911 1,988
03/01/2026 to 03/31/2026 ^(1)^ Platts 541,711 (541,359) 352 222 (129)
04/01/2026 to 04/30/2026 Platts 576,522 (574,310) 2,212 2,203 9
05/01/2026 to 05/31/2026 Platts 214,439 (213,406) 1,033 1,037 (3)
06/01/2026 to 06/30/2026 Platts 137,883 (137,401) 482 481 2
1,470,555 (1,466,476) 4,079 27,280 40,578 3,721 31,019 1,329 199

All values are in US Dollars.

(1) The maturity of the operation occurred on March 31, 2026 and its liquidation in early April 2026.

The movement of the amounts related to cash flow hedge accounting - "Platts" index recorded in shareholders' equity on March 31, 2026 is shown as follows:

12/31/2025 Movement Realization 03/31/2026
Cash flow hedge  –  “Platts” (29,977) 60,978 (27,280) 3,721
Income tax and social contribution on cash flow hedge 10,192 (20,732) 9,275 (1,265)
Fair Value of cash flow hedge - Platts, net (19,785) 40,246 (18,005) 2,456

The cash flow hedge - "Platts" index was fully effective since the contracting of derivative instruments.

To support the designations, the Company prepared formal documentation indicating how the cash flow hedge accounting designation - "Platts" index aligns with CSN's risk management objectives and strategy, identifying the protection instruments used, the hedge object, the nature of the risk to be protected, and demonstrating the expectation of high effectiveness of the designated relationships. Iron ore derivative instruments ("Platts" index) were designated in amounts equivalent to the portion of future sales, comparing the designated amounts with the expected and approved amounts in the budgets of the Management and Board.

(In thousands of Reals, unless stated otherwise)

b) Cash flow Hedge Accounting

Foreign Exchange Hedge

The Company and its subsidiary CSN Mineração formally designate cash flow hedge relationships to protect highly probable future flows exposed to the dollar related to sales made in dollars.

With the objective of better reflecting the accounting effects of the foreign exchange hedge strategy in the results, CSN and its subsidiary CSN Mineração designated part of their dollar liabilities as a hedge instrument for their future exports. As a result, the exchange rate variation from designated liabilities will be temporarily recorded in shareholders' equity and will be transferred to the income statement when the respective exports occur, thus allowing the recognition of dollar fluctuations on the liability and exports to be recorded at the same time. It is emphasized that the adoption of this hedge accounting does not imply the contracting of any financial instrument.

The table below presents the summary of hedging relationships as of March 31, 2026:

03/31/2026
Designation Date Hedging Instrument Hedged item Type of hedged risk Hedged period Exchange rate on designation Designated amounts (US$’000) Amortized part (USD'000) Effect on Result (R$'000) Impact on Shareholders' equity (R$'000)
07/31/2019 Bonds and Export prepayments in US$ to third parties Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate January 2020 - April 2026 3.7649 1,342,761 (1,248,561) 405,465 (137,014)
1/10/2020 Bonds Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate March 2020 to November 2025 until December 2050 4.0745 1,416,000 (1,416,000) (1,214,600)
01/28/2020 Bonds Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate March 2027 - January 2028 4.2064 1,000,000 (1,013,000)
6/1/2022 Bonds and Export prepayments in US$ to third parties Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate June 2022 - April 2032 4.7289 1,145,000 (360,000) (385,043)
12/1/2022 Bonds Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate December 2022 - June 2031 5.0360 490,000 (37,000) (83,080)
12/1/2022 Advance on foreign exchange contract Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate December 2022 - December 2025 5.2565 100,000 (100,000)
05/16/2024 Export Prepayments in US$ with third parties, ACC and Bonds Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate September 2024 - March 2035 5.1270 1,202,000 (266,600) 4,714 (86,431)
6/6/2024 Advance on foreign exchange contract Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate June 2024 - February 2025 5.2700 30,000 (30,000)
06/25/2024 Advance on foreign exchange contract Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate June 2024 - February 2025 5.4405 10,000 (10,000)
Total recognized at the parent company 6,735,761 (3,468,161) 410,179 (2,919,168)
6/1/2022 Export prepayments in US$ to third parties Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate June 2022 - May 2033 4.7289 878,640 (269,350) 4,341 (298,857)
12/1/2022 Export prepayments in US$ to third parties Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate December 2022 - June 2027 5.0360 70,000 (13,032)
05/16/2024 Export prepayments in US$ to third parties Part of the highly probable future monthly iron ore exports Foreign exchange - R$ vs. US$ spot rate August 2025 - March 2035 5.1270 208,717 (88,372) 618 (11,120)
Total recognized in the consolidated 7,893,118 (3,825,883) 415,138 (3,242,177)
---

(In thousands of Reals, unless stated otherwise)

The net balance of the amounts designated and previously amortized in US Dollars totals US$ 4,067,235 (US$ 4,384,011 as of December 31, 2025).

In the hedge relationships described above, the values of the debt instruments were fully designated for equivalent portions of iron ore exports.

As of March 31, 2026, the hedging relationships established by the Company were effective, according to the prospective and retrospective tests carried out. Thus, no reversal due to ineffectiveness of cash flow hedge accounting was recorded.

c) Net Overseas Investment Hedge

The information related to the hedge of net investment abroad has not changed in relation to that disclosed in the Company's financial statements as of December 31, 2025. The balance recorded on March 31, 2026 and December 31, 2025 in shareholders' equity is R$6,292,800.

d) Hedge Accounting Transactions

The movement of the amounts related to cash flow hedge accounting recorded in shareholders' equity on March 31, 2026, is shown as follows:

Consolidated
12/31/2025 Movement Realization 03/31/2026
Cash flow hedge (4,900,465) 1,243,150 415,138 (3,242,177)
Income tax and social contribution on cash flow hedge 1,666,160 (422,672) (141,147) 1,102,341
Fair Value of cash flow accounting, net taxes (3,234,305) 820,478 273,991 (2,139,836)
Parent Company
12/31/2025 Movement Realization 03/31/2026
Cash flow hedge (4,341,748) 1,012,401 410,179 (2,919,168)
Income tax and social contribution on cash flow hedge 1,476,195 (344,217) (139,461) 992,517
Fair Value of cash flow accounting, net taxes (2,865,553) 668,184 270,718 (1,926,651)
iv) Credit risks
--- ---

The exposure to credit risks of financial institutions observes the parameters established in the financial policy. The Company's practice is the detailed analysis of the equity and financial situation of its customers and suppliers, the establishment of a credit limit and the permanent monitoring of its outstanding balance.

Regarding financial investments, the Company only makes investments in institutions with low credit risk assessed by credit rating agencies. Since part of the resources is invested in repurchase agreements that are backed by Brazilian government securities, there is also exposure to the credit risk of the Brazilian State.

(In thousands of Reals, unless stated otherwise)

Regarding credit risk exposure in trade and other receivables, the Company has a credit risk committee where each new customer is individually analyzed for their financial condition before credit limits and payment terms are granted. This is periodically reviewed according to the procedures specific to each business area.

v) Liquidity Risk

It is the risk that the Company may not have sufficient net funds to honor its financial commitments as a result of the mismatch of term or volume between expected receipts and payments.

Future receipt and payment premises are established to manage cash liquidity in domestic and foreign currencies, which are monitored on a day-to-day basis by the Treasury department. Payment schedules for long-term installments of loans, financing and debentures are presented in note 13.

Amounts below represent contractual maturities for financial liabilities including interest:

Consolidated
At March 31, 2026 Ref. Less than one year From one to two years From two to five years Over five years Total
Loans, financing and debentures 13.b 9,166,269 6,859,829 19,851,790 15,200,342 51,078,230
Lease liabilities 15 212,434 202,232 198,579 438,326 1,051,571
Derivative transactions 18 1,731 141,085 142,816
Trade payables 16 6,531,907 68,555 6,600,462
Trade payables - Forfaiting 16.a 2,410,807 2,410,807
Dividends and interest on capital 18 1,140,000 1,140,000
Concessions to be paid 18 13,336 13,350 40,050 24,371 91,107
19,476,484 7,143,966 20,090,419 15,804,124 62,514,993

Fair Values of Assets and Liabilities in Relationto Book Value

Assets and liabilities measured at fair value through profit or loss are recognized under financial results. However, when designated for hedge accounting operations, fair value adjustments are recorded under other comprehensive income up until the moment they are realized, when they are then recorded under other operating income (expenses), according to the nature of the operation.

The amounts are recorded in the financial statements at their book value, which are substantially similar to those that would be obtained if they were traded in the market. The fair values of other long-term assets and liabilities do not differ significantly from their carrying amounts, except for the amounts below.

The estimated fair value for certain consolidated long-term loans and financing were calculated at current market rates, considering the nature, term and risks similar to those of the registered contracts, as follows:

03/31/2026 12/31/2025
Closing Balance Fair value Closing Balance Fair value
Fixed Rate Notes (*) 18,791,348 12,780,546 19,728,321 16,958,019

(*) Source: Bloomberg.

(In thousands of Reals, unless stated otherwise)

14.c) Protective instruments: Derivatives

Position of the derivative financial instrument’sportfolio

Foreign exchange swap CDI x Dollar

In October 2023, the Company entered into a new swap agreement with the purpose of mitigating the risk associated with an Export Credit Note (ECN) acquired during the same period, whose maturity is scheduled for October 2028, and which has a principal amount of R$ 680,000.

In January 2025, the Company entered into a new swap agreement with the purpose of mitigating the risk associated with an NCE acquired during the same period, whose maturity is scheduled for January 2028, and which has a principal amount of US$ 50,000.

Real x Dollar Foreign Exchange Swap

The Subsidiary CSN Cimentos Brasil, after receiving foreign currency loan in the amount of US$ 115,000, contracted derivative instruments in order to hedge again foreign exchange exposure to the dollar. This transaction was settled in June 2025.

In July 2024, CSN Cimentos Brasil again, after obtaining a foreign currency loan in the amount of US$ 50,000, contracted derivative transactions to hedge its exposure against the dollar. These transactions will mature in July 2027.

Interest swap CDI x IPCA

CSN Mineração, CSN Cimentos Brasil and CSN issued debentures during the years 2021, 2022 and 2023, respectively, and contracted derivative operations to protect their exposure to IPCA. The CSN Mineração contracts have staggered maturities between 2031 and 2037, the CSN Cimentos contracts mature in 2038, and CSN's between 2030 and 2038.

Below is the position of derivatives:

Consolidated
03/31/2026 03/31/2025
Appreciation (R) Fair value (market) Effect on financial result (note28)
Instrument Maturity Functional Currency Notional amount Asset position Liability position Amounts receivable / (payable)
Exchange rate swap
Exchange rate swap CDI x Dollar - CSN 2028 Real 975,000 1,036,134 (1,117,655) (81,521) 35,598 2,223
Dollar x Real swap - CSN Cimentos Brasil 2027 Dollar 50,000 273,183 (297,994) (24,811) (22,217) (57,108)
Exchange rate swap Dollar x CDI - Grupo Estrela 2027 Real 179,453 184,819 (217,928) (33,109) (17,982)
Total Exchange rate Swap 1,494,136 (1,633,577) (139,441) (4,601) (54,885)
Interest rate swap
Interest rate (Debentures) CDI x IPCA - CSN 2030 to 2039 Real 2,012,358 2,177,825 (2,212,097) (34,272) (14,204) 6,968
Interest rate (Debentures) CDI x IPCA - CSN Mineração 2031 to 2037 Real 2,400,000 2,735,520 (2,662,099) 73,421 (14,689) 9,667
Interest rate (Debentures) CDI x IPCA - CSN Cimentos Brasil 2032 Real 1,200,000 1,397,946 (1,276,551) 121,395 (614) 4,816
Total interest rate (Debentures) CDI x IPCA 6,311,291 (6,150,747) 160,544 (29,507) 21,451
7,805,427 (7,784,324) 21,103 (34,108) (33,434)

All values are in US Dollars.

(In thousands of Reals, unless stated otherwise)

Classification of Derivatives in the Balance Sheetand Income Statement

03/31/2026 03/31/2025 03/31/2026 03/31/2025 03/31/2026 03/31/2025
Instruments Assets Liabilities Other operating income expenses Other comprehensive income Financial income (expenses), net (note 28)
Current Total Current Non-current Total
Iron ore derivative 4,080 4,080 27,280 40,578 3,721 31,031 1,327 199
Exchange rate swap CDI x Dollar 3,375 3,375 (1,731) (141,085) (142,816) 17,617 61,037
Exchange rate swap CDI x IPCA ^(1)^ 160,544 160,544 (29,508) 21,450
Dollar x Real swap (22,217) (115,921)
7,455 7,455 (1,731) 19,459 17,728 27,280 40,578 3,721 31,031 (32,781) (33,235)

(1) CDI x IPCA SWAP derivative instruments are fully classified under the loans and financing group since they are linked to debentures in order to hedge against exposure to IPCA.

14.d) Investments in Securities Measured at Fair Value Through Profit orLoss

The Company holds common (USIM3) and preferred (USIM5) shares of Usiminas Siderúrgica de Minas Gerais S.A. (“Usiminas”). Usiminas shares are classified as current assets in financial investments and at fair value, based on the market price quotation on B3.

According to the Company's policy, gains and losses resulting from changes in stock prices are recorded directly in the income statement under financial income for shares classified as financial investments and under other operating income and expenses for shares classified as investments.

i) Stock Market Price Risks
Class of shares 03/31/2026 12/31/2025 03/31/2026 03/31/2025
--- --- --- --- --- --- --- --- --- --- ---
Quantity Interest (%) Share price Closing Balance Quantity Equity interest (%) Share price Closing Balance Profit loss (note 28)
USIM3 35,192,508 4.99% 6.66 234,382 35,192,508 4.99% 5.96 209,747 24,635 30,921
USIM5 27,336,117 4.99% 6.74 184,246 27,336,117 4.99% 5.95 162,650 21,595 19,852
418,628 372,397 46,230 50,773

The Company is exposed to the risk of changes in share prices due to investments measured at fair value through profit or loss that have their quotations based on market price on B3.

Sensitivity Analysis for Stock Price Risks

We present below the sensitivity analysis for the risks related to the stock price variation. The Company evaluated two distinct scenarios for the impact of price fluctuations: Scenario 1 (extreme optimistic) forecasts a horizon of price appreciation, and Scenario 2 (extreme pessimistic) considers a horizon of deterioration in price volatility. The calculation was based on the closing price of the shares on March 31, 2026, using assumptions based on both the dispersion of historical variations in prices and projections prepared by Management.

(In thousands of Reals, unless stated otherwise)

The effects on the result, considering the probable scenarios, 1 and 2 are shown below:

03/31/2026
Class of shares Quantity Share prince on 03/31/2026 Extreme Optimistic Scenario share price Extreme Pessimistic Scenario share price Closing Balance Extreme Optimistic Scenario (1) Extreme Pessimistic Scenario (2)
USIM3 35,192,508 6.66 7.49 5.79 234,382 29,137 (30,727)
USIM5 27,336,117 6.74 7.57 5.93 184,245 22,646 (22,049)
418,627 51,783 (52,776)
14.e) Capital Management

The Company seeks to optimize its capital structure with the purpose of reducing its financial costs and maximizing return to its shareholders. The following chart demonstrates the evolution of the Company's consolidated capital structure, with financing through equity and third-party capital:

Thousands of Reais 03/31/2026 12/31/2025
Shareholder's equity (equity) 15,894,283 15,736,350
Borrowings and Financing (Third-party capital) 50,435,129 52,924,547
Gross Debit/Shareholder's equity 3.17 3.36
15. LEASE LIABILITIES
--- ---

The lease liabilities are presented below:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Leases 2,397,148 2,469,723 41,269 43,430
Adjusted present value - Leases (1,345,577) (1,375,984) (5,585) (6,335)
1,051,571 1,093,739 35,684 37,095
Classified:
Current 212,434 238,702 12,307 11,525
Non-current 839,137 855,037 23,377 25,570
1,051,571 1,093,739 35,684 37,095

Through its subsidiaries, the Company holds leases for port terminals in Itaguaí: the Solid Bulk Terminal (TECAR), used for the loading and unloading of iron ore and other minerals, and the Container Terminal (TECON), with remaining lease terms of 21 and 25 years, respectively, and a concession for railway operations using the Northeast network with a remaining term of 2 years, as well as a land lease agreement located in Taubaté, São Paulo, for the expansion of operations in the Steel segment with a remaining term of 17 years.

Additionally, the Company has leasing contracts for operational equipment, mainly used in mining, cement, and steel operations, and properties used as operational facilities and administrative and sales offices in various locations where the Company operates, with remaining terms of 1 to 19 years.

(In thousands of Reals, unless stated otherwise)

The present value of future obligations was measured using the implicit rate observed in the contracts, and for contracts that did not have a rate, the Company applied the incremental rate of loans – IBR, both in nominal terms.

The average rates used in measuring new lease liabilities in the consolidated and parent company are demonstrated in the table below:

03/31/2026
Contract term (in years) Incremental Rate (p.a.)
1 14.62%
2 13.86%
3 15.41%

The reconciliation of lease liabilities is shown in the table below:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Opening balance 1,093,739 840,305 37,095 38,453
New leases 21,890 72,305 1,041
Contract review 4,006 244,543 8,238
Write-off (1,472) (12,050)
Payments (92,652) (371,467) (3,280) (12,997)
Interest appropriated 31,084 115,529 828 3,401
Acquisition of stakes in subsidiaries 209,178
Exchange variation (5,024) (4,604)
Net balance 1,051,571 1,093,739 35,684 37,095

The estimated future minimum payments for the lease agreements include determinable variable payments, which are certain to occur based on minimum performance and contractually fixed rates.

As of March 31, 2026, the expected payments are the followings:

Consolidated
Less than one year Between one and five years Over five years Total
Leases 240,072 765,016 1,392,060 2,397,148
Adjusted present value - Leases (27,638) (342,534) (975,405) (1,345,577)
212,434 422,482 416,655 1,051,571
---

(In thousands of Reals, unless stated otherwise)

· Recoverable PIS and COFINS

Lease liabilities were measured by the value of the considerations with suppliers, that is, without considering tax credits that apply after payment. The potential right to PIS and COFINS embedded in the lease liability is shown below:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Leases 2,311,988 2,376,597 38,969 40,979
Adjusted present value - Leases (1,341,435) (1,371,252) (5,228) (5,938)
Potencial PIS and COFINS credit 213,859 219,835 3,605 3,791
Adjusted present value – Potential PIS and COFINS credit (124,083) (126,841) (484) (549)

Lease payments not recognizedas liabilities:

The Company chose not to recognize lease liabilities in contracts with a term of less than 12 months and for low value assets. Payments made for these contracts are recognized as expenses when incurred.

The Company has lease contracts for port terminals (TECAR and TECON) and a concession contract for the operation and development of public rail freight transport services in the Northeast Network I (FTL). Although these contracts establish minimum performance requirements, it is not possible to determine their cash flow since the payments are entirely variable and will only be known when they occur. In such cases, payments will be recognized as expenses when incurred.

Expenses related to payments not included in the measurement of the lease liability are:

Consolidated Parent Company
03/31/2026 03/31/2025 03/31/2026 03/31/2026
Lower Assets value 2,162 3,665 1,068 2,405
Variable lease payments 70,549 80,663
72,711 84,328 1,068 2,405
16. TRADE PAYABLES
--- ---
Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Trade payables 6,708,580 7,323,417 4,401,670 4,005,857
(-) Adjusted present value (108,118) (93,681) (76,906) (60,933)
6,600,462 7,229,736 4,324,764 3,944,924
Classified:
Current 6,531,907 7,162,929 4,321,780 3,941,596
Non-current 68,555 66,807 2,984 3,328
6,600,462 7,229,736 4,324,764 3,944,924

(In thousands of Reals, unless stated otherwise)

16.a) Trade payables – Forfaiting
Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
In Brazil 1,990,180 2,231,266 1,186,317 1,250,533
Abroad 420,627 673,752 420,628 673,752
2,410,807 2,905,018 1,606,945 1,924,285

The Company discloses and classifies in a specific group its forfaiting operations with suppliers where the nature of the securities continue to be part of the Company's operating cycle. These transactions are negotiated with financial institutions to enable the Company's suppliers to anticipate receivables arising from sales of goods and, consequently, to extend the payment terms mostly from 180 days to 360 days of the Company's own obligations.

The table below provides a comparison of invoice payment terms with and without reverse factoring operations, dealing only with merchandise acquisitions, for the base date of March 31, 2026:

Consolidated Consolidated
03/31/2026 12/31/2025
Trade payables Forfaiting No  Forfaiting Forfaiting No  Forfaiting
Due between 1 and 180 days 1,322,964 6,489,118 2,128,326 5,275,445
Due between 181 to 360 days 1,087,843 42,789 776,693 1,887,484
Over 360 days 68,555 66,807
Total 2,410,807 6,600,462 2,905,019 7,229,736

Impact of variations without effect on cash as of March 31, 2026:

Consolidated
03/31/2026 03/31/2025
Exchange variation (13,707) 2,751
Interest Appropriation 19,877 13,998
Total 6,170 16,749

(In thousands of Reals, unless stated otherwise)

17. ADVANCES FROM CUSTOMERS

Contract liabilities classified as current and non-current liabilities are comprised as follows:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Iron ore 12,581,551 11,597,794
Others 1,736,602 1,776,909 1,212,013 1,220,004
14,318,153 13,374,703 1,212,013 1,220,004
Classified:
Current 4,530,955 4,347,937 563,043 481,905
Non-current 9,787,198 9,026,766 648,970 738,099
14,318,153 13,374,703 1,212,013 1,220,004
18. OTHER PAYABLES (CURRENT AND NON-CURRENT)

The other payables classified in current and non-current liabilities are comprised as follows:

Consolidated Parent Company
Ref. Current Non-current Current Non-current
03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Related party liabilities 63 50,241 575,361 622,306 288,817 312,889
Derivative financial instruments 14 1,731 67,304 141,085 153,507 84,896 117,120
Dividends and interest on capital ^(1)^ 14 1,140,000 358,040 6,047 6,059
Liabilities fron the business combination 305,285 377,411 495,665 470,890 135,022 129,688 431,523 457,090
Taxes in installments 30,831 30,727 85,792 88,906 17,460 17,265 48,972 50,026
Profit sharing - employees 413,428 327,663 214,818 170,735
Taxes payable 10,353 10,266 10,353 10,266
Provision for consumption and services 261,243 275,577 31,763 30,882
Trade payables 16 68,555 66,807 2,984 3,328
Lease liabilities 15 212,434 238,702 839,137 855,037 12,307 11,525 23,377 25,570
Concessions to be paid 14 13,336 13,350 77,771 78,419
Others payables ^(2)^ 147,042 143,471 807,590 525,838 52,982 56,319 509,623 217,060
2,525,393 1,882,486 2,525,948 2,249,670 1,045,760 1,044,779 1,400,545 1,193,349

(1) Refers, for the most part, to dividends and interest on shareholders' equity resolved by the subsidiary CSN Mineração. Part of this balance was advanced by a Related Financial Institution, while the remaining amount represents balances payable to non-controlling shareholders.

(2) Under Non-Current Assets, this refers primarily to a call and put option agreement regarding the remaining 30% stake held by non-controlling interests in the Estrela Group, which grants minority shareholders the right to sell ("Put") and the Company the obligation to acquire said equity interests, the balance of which as of March 31, 2026, is R$ 298,662 in the Parent Company and in the Consolidated Financial Statements.

19. INCOME TAX AND SOCIAL CONTRIBUTION
19.a) Income tax and social contribution recognized in profit or loss:

Income tax and social contributions recognized in profit or loss for the period are as follows:

Consolidated Parent Company
03/31/2026 03/31/2025 03/31/2026 03/31/2025
Income tax and social contribution income (expense)
Current (115,291) (203,771) - -
Deferred 572,776 434,901 536,938 353,388
457,485 231,130 536,938 353,388
---

(In thousands of Reals, unless stated otherwise)

The reconciliation of expenses related to income tax and social contributions and consolidated and parent company and the product of the current rate on profit before income tax (IRPJ) and social contribution (CSLL) are shown below:

Consolidated Parent Company
03/31/2026 03/31/2025 03/31/2026 03/31/2025
Profit/(Loss) before income tax and social contribution (1,012,508) (962,710) (1,152,469) (972,534)
Tax rate 34% 34% 34% 34%
Income tax and social contribution at combined statutory rate 344,253 327,321 391,839 330,662
Adjustment to reflect the effective rate:
Equity in results of affiliated companies^(1)^ 49,486 36,622 129,956 30,388
Effect of differentiated rates and tax-exempt profits in investments 75,768 (102,350)
Income taxes and social contribution on foreign profit (1,978) (1,978)
Indebtdness limit (727) (727)
Tax incentives 6,737 5,921
Recognition/(reversal) of tax credits (26,468) (13,523)
Other permanent deductions (add-backs) 8,436 (20,883) 15,870 (5,684)
Income tax and social contribution in net income for the period 457,485 231,130 536,938 353,388
Effective tax rate 45% 24% 47% 36%
19.b) Deferred Income Tax and Social Contribution:
--- ---

Deferred income tax and social contribution balances are as follows:

Consolidated Parent Company
Balance at January 01, 2025 6,803,997 4,750,333
Recognized in profit and loss 1,094,263 1,274,539
Recognized in equity (1,387,336) (1,138,951)
Balance at December 31, 2025 6,510,924 4,885,921
Recognized in profit and loss 572,776 536,938
Recognized in equity (550,405) (483,677)
Balance at March 31, 2026 6,533,295 4,939,182

The Company's corporate structure includes foreign subsidiaries, the income of which is taxed in the respective countries. During the period between 2021 and 2025, these subsidiaries generated profits in the amount of R$ 8,276. If the Brazilian tax authorities understand that these profits are subject to additional taxation in Brazil through income tax and social security contributions, these amounts, if due, would total approximately R$ 2,814.

The Company, based on the position of its legal advisors, assessed only as possible the probability of loss in case of a possible tax challenge and, as a result, there was no provision was recognized in Financial Statements.

Furthermore, Management evaluated the precepts of IFRIC 23 - "Uncertainty Over Income Tax Treatments" and recognized in 2021 the credit for the unconstitutionality of IRPJ and CSLL incidence on SELIC interest of mora values received due to tax undue repetition.

A sensitivity analysis of tax credit consumption was conducted considering a variation of macroeconomic assumptions, operational performance, and liquidity events. Thus, considering the results of the study, which indicates that it is probable the existence of taxable income to use the balance of deferred income tax and social contribution.

(In thousands of Reals, unless stated otherwise)

19.c) Changes in Deferred Income Tax and Social Contribution

Deferred income tax and social contribution balances are as follows:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Deferred
Income tax losses 4,693,217 4,578,638 2,968,068 2,657,671
Social contribution tax losses 1,717,206 1,585,078 1,094,886 983,143
Temporary differences 122,872 347,208 876,228 1,245,107
Tax, social security, labor, civil and environmental provisions 382,768 391,345 159,382 163,124
Estimated losses on assets 388,110 375,880 247,338 234,210
Gains/(Losses) on financial assets 271,011 296,640 229,563 261,604
Actuarial Liabilities (Pension and Health Plan) 147,940 141,088 132,494 128,915
Provision for consumption and services 10,461 22,911 6,532 15,074
Cash Flow Hedge and Unrealized Exchange Variations 426,004 886,799 259,123 628,018
(Gain) on loss of control of Transnordestina (224,096) (224,096) (224,096) (224,096)
Fair Value SWT/CBL Acquisition (149,490) (149,490)
Business combination (1,035,964) (1,462,402) (688,565) (721,992)
Unrealized results – transactions between related parties 783,127 783,127 799,366 799,366
Acquisition of stakes in subsidiaries (44,909)
(Losses)/Estimated reversal for deferred income tax and social contribution credits (188,975)
Others^^ (114,294) (525,619) (39,116)
Non-established income tax and social contribution (762,705)
Total 6,533,295 6,510,924 4,939,182 4,885,921
Total Deferred Assets 7,104,779 7,100,375 4,939,182 4,885,921
Total Deferred Liabilities (571,484) (589,451)
Total Deferred 6,533,295 6,510,924 4,939,182 4,885,921
19.d) Income Tax and Social Contribution Recognized in Shareholders' Equity
--- ---

Income tax and social contribution recognized directly in equity are shown below:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Income tax and social contribution
Actuarial gains on defined benefit pension plan 50,573 50,702 43,730 43,730
Exchange differences on translating foreign operations (325,350) (325,350) (325,350) (325,350)
Cash flow hedge 1,012,951 1,590,839 992,517 1,476,195
Gain on sale of shares (1,158,081) (1,158,102) (1,158,081) (1,158,102)
(419,907) 158,089 (447,184) 36,473
---

(In thousands of Reals, unless stated otherwise)

20. PRIVISIONS FOR TAX, SOCIAL SECURITY, LABOR, CIVIL,ENVIROMENTAL PROVISIONS AND JUDICIAL DEPOSITS

Claims of different nature are being challenged at the appropriate courts. The details of provisioned values and respective judicial deposits related to these actions are presented below:

Consolidated Parent Company
Accrued liabilities Judicial deposits Accrued liabilities Judicial deposits
03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Tax 84,748 89,522 178,647 182,569 15,624 15,891 67,351 71,763
Social security 13,643 13,533 13,643 13,533
Labor 478,428 486,045 379,748 372,571 172,689 170,253 142,764 139,265
Civil 290,868 224,984 34,406 34,361 123,026 117,997 15,524 15,488
Environmental 55,681 60,092 4,981 6,317 18,219 23,502 277
Deposit of a guarantee 23,208 25,194
923,368 874,176 620,990 621,012 343,201 341,176 225,639 226,793
Classified:
Current 56,009 61,455 35,235 40,225
Non-current 867,359 812,721 620,990 621,012 307,966 300,951 225,639 226,793
923,368 874,176 620,990 621,012 343,201 341,176 225,639 226,793

The movement of tax, social security, labor, civil and environmental provisions in the period ended March 31, 2026 can be demonstrated as follows:

Consolidated
Current + Non-current
Nature 12/31/2025 Additions Accrued charges Net utilization of reversal 03/31/2026
Tax 89,522 17,080 1,638 (23,492) 84,748
Social security 13,533 110 13,643
Labor 486,045 11,451 18,415 (37,483) 478,428
Civil 224,984 56,959 12,493 (3,568) 290,868
Environmental 60,092 512 1,116 (6,039) 55,681
874,176 86,002 33,772 (70,582) 923,368
Parent Company
--- --- --- --- --- ---
Current + Non-current
Nature 12/31/2025 Additions Accrued charges Net utilization of reversal 03/31/2026
Tax 15,891 2,397 645 (3,309) 15,624
Social security 13,533 110 13,643
Labor 170,253 5,335 7,070 (9,969) 172,689
Civil 117,997 303 6,254 (1,528) 123,026
Environmental 23,502 1 518 (5,802) 18,219
341,176 8,036 14,597 (20,608) 343,201

Provisions for taxes, social security, labor, civil and environmental matters have been estimated by management and substantially substantiated by legal counsel, and only those causes that are considered probable of loss are recorded. These provisions also include tax liabilities arising from actions taken at the Company's initiative, plus SELIC (Special System for Settlement and Custody) interest.

(In thousands of Reals, unless stated otherwise)

Tax Proceedings

The main legal proceedings considered by external legal consultants as having a probable loss probability, in which CSN or its subsidiaries are parties, of a tax nature are: (i) some ISS tax infraction notices; (ii) divergences between calculated and collected ICMS; and (iii) Compensation requests not approved due to lack of credit rights.

Labor lawsuits

The Group appears as a defendant in labor claims. Most of the claims in these lawsuits relate to subsidiary and/or joint liability, equal pay, hazard and danger pay allowances, overtime, health plans, compensation claims for alleged occupational diseases or work accidents, intra-day break periods, and differences in profit sharing for the years 1997 to 1999 and 2000 to 2003.

Throughout the period ended March 31, 2026, there were changes in additions and write-offs of labor proceedings resulting from definitive closure, in addition to the constant review of the Company's accounting estimates in relation to provisions and contingencies, which consider the different nature of the claims involved, as established in the Company's accounting policies.

Civil Lawsuits

Among the civil lawsuits in which he appears as a defendant, there are mainly lawsuits with a claim for compensation. Such processes, in general, are resulting from work accidents, occupational diseases, contractual discussions related to the Group's industrial activities, real estate actions, health plans.

Environmental Processes

The main environmental proceedings considered by external legal consultants as having probable loss probability, in which CSN or its subsidiaries are parties, are (i) administrative violation notices for alleged environmental infractions; (ii) annulment lawsuits and tax foreclosures resulting from environmental fines; and (iii) procedural fines for alleged non-compliance with court orders.

Among the environmental administrative/judicial proceedings in which the Company is a defendant are administrative procedures aimed at verifying possible environmental irregularities and regularizing environmental licenses. In the judicial sphere, there are actions to enforce fines imposed due to such alleged irregularities and public civil actions seeking regularization combined with compensation, which consist of environmental restoration in most cases. Such processes are generally derived from discussions of supposed environmental impacts related to the Company's industrial activities.

(In thousands of Reals, unless stated otherwise)

Administrative and Judicial Proceedings

The Company does not make provisions for legal proceedings whose expectation of the Management, based on the opinion of legal advisors, is of possible loss. The following table shows a summary of the balance of the main matters classified as possible risk compared to the balance of March 31, 2025 with December 31, 2025.

The Company has other cases classified by its legal counsel as having a possibility of loss; therefore, they represent present obligations for which an outflow of resources is not probable. As of March 31, 2026, these amounted to R$ 48,466,842 (R$ 47,419,219 as of December 31, 2025), of which R$ 3,134,584 relates to labor lawsuits (R$ 2,894,042 as of December 31, 2025), R$ 4,118,755 to civil lawsuits (R$ 3,845,589 as of December 31, 2025), R$ 39,127,340 in tax proceedings (R$ 38,597,353 as of December 31, 2025), and R$ 1,886,163 in environmental proceedings (R$ 2,082,235 as of December 31, 2025).

Consolidated
03/31/2026 12/31/2025
Notice of Violation and Imposition of Fine (AIIM) /Tax Foreclosure - RFB - IRPJ/CSLL - Capital Gain for alleged sale of equity interest in subsidiary NAMISA 6,670,018 6,554,452
Notice of Infraction and Imposition of a Fine (AIIM) /Tax Enforcement Proceedings - RFB - IRPJ/CSLL - Exclusion of goodwill deductions generated during reverse merger of Big Jump and Namisa 3,567,437 3,512,216
Notice of Violation and Imposition of Fine (AIIM) /Tax Foreclosure - RFB - IRPJ/CSLL - Disallowance of prepayment interest arising from iron ore supply and port services contracts 2,299,196 2,264,620
Notices of Infraction and Imposition of a Fine (AIIM) / Writ of Mandamus - RFB - IRPJ/CSLL - Profits earned overseas in 2008, 2010, 2011, 2012, 2014, 2015, 2016, 2017 and 2018 5,969,353 5,858,583
Unapproved compensation - RFB - IRPJ/CSLL, PIS/COFINS and IPI 2,335,848 2,319,108
Unapproved tax credits - RFB - Disallowance of credits under Topic 69/STF (ICMS included in the PIS/COFINS tax base) 767,874 751,209
ICMS - SEFAZ/RJ - Questions regarding sales for Incentives Zone 1,338,624 1,309,079
Notice of Violation and Imposition of Fine (AIIM) - RFB - Disallowance of PIS/COFINS Credits for inputs and freight 1,918,303 1,875,734
CFEM - difference of understanding between CSN and ANM on the calculation basis 1,750,924 1,715,523
Notice of Violation and Imposition of Fine (AIIM) - RFB - Collection IRRF - Business Combinations CMIN 2015 225,392 221,203
ICMS - SEFAZ/RJ - ICMS Credits for acquisition of Electric Energy Industrialization 44,660 43,716
Notice of Violation and Imposition of Fine (AIIM) - RFB - IRPJ/CSLL - Disallowance of deductions of goodwill generated in the acquisition of LACIM and Cimentos Mauá 431,926 434,203
ICMS - SEFAZ/RJ - Exclusion of Ore Transfer credits 727,336 705,480
ICMS - SEFAZ/RJ - Disallowance of credits on purchase of intermediate products 510,483 497,950
Disallowance of tax loss and negative calculation base resulting from adjustments in SAPLI - RFB 733,139 871,652
Tax Assessment and Penalty Notices (AIIM) - RFB - IRPJ/CSLL - Transfer Pricing 74,951 73,556
ICMS - SEFAZ/RJ - Transfer of imported raw material for a value lower than the TECAR import document 467,666 458,694
Tax Assessment and Penalty Notices (AIIM) / Action for Annulment - RFB - IRRF - Capital gains of CFM sellers located abroad 165,990 163,996
Other tax proceedings (federal, state and municipal taxes) 8,454,162 8,357,638
Social security lawsuits 674,060 751,191
Action to discuss the balance of the construction contract - Tebas 679,699 650,979
Action related to charges under electricity invoice - Light 584,783 551,756
Action that discusses Negotiation of energy sales - COPEN - CEEE-G 251,711 247,883
Lawsuit challenging the penalty imposed by CADE on the company acquired by the CSN Group for alleged participation in a cement cartel 519,000 510,404
---

(In thousands of Reals, unless stated otherwise)

Other civil proceedings 2,083,562 1,958,195
Labor and social security proceedings 3,134,584 3,001,846
Tax Enforcement Proceedings Fine Volta Grande IV 178,421 168,746
ACP Landfill Marcia I 306,389 306,389
Notice of IEF Commitment Agreement 337,951 337,951
Other environmental lawsuits 1,063,402 894,523
Reflecting the acquisition of a stake in the Estrela Group 50,745
48,266,844 47,419,220

In the 1st quarter of 2021, the Company was notified of the start of an arbitration proceeding based on an alleged breach of iron ore supply contracts. The opposing party's claim at that time totaled approximately US$1 billion, and the Company understands the allegations presented to be unfounded by the complete absence of damages, based on the assessment of its legal advisors. The Company wishes to inform that it has prepared, together with its legal advisors, a response to the arbitration request and is currently preparing its defense. It also wishes to clarify that discussions involve ongoing arbitration disputes initiated by both parties. It is also estimated that arbitration will be completed in approximately 9 months. The relevance of the proceedings for the Company is related to the value attributed to the cause and the possible financial impact.

The Company has provided judicial guarantees (Surety Bonds) in the total amount, adjusted as of March 31, 2026, of R$10,911 (R$11,020 as of December 31, 2025), in accordance with current procedural law.

Evaluations carried out by legal advisors have defined these administrative and judicial proceedings as a possible risk of loss, and a provision has not been established in accordance with Management's judgment and accounting practices adopted in Brazil.

21. PROVISIONS FOR ENVIRONMENTAL LIABILITIES AND ASSETRETIREMENT OBLIGATIONS

The balance of provisions for environmental liabilities and asset decommissioning can be shown as follows:

Consolidated Parent Company
03/31/2026 12/31/2025 03/31/2026 12/31/2025
Environmental liabilities 119,133 119,664 110,674 111,789
Asset retirement obligations 1,098,328 1,067,945
1,217,461 1,187,609 110,674 111,789

As of March 31, 2026, a provision remains in place to cover expenses related to services for the investigation and environmental remediation of potentially contaminated, degraded, and currently exploited areas for which the Company is responsible in Brazil. Expense estimates are reviewed periodically, adjusting, whenever necessary, the amounts already accounted for. These are Management's best estimates considering environmental recovery studies and projects. These provisions are recorded in the other operating expenses account.

Some contingent environmental liabilities are monitored by the environmental area and have not been provisioned because their characteristics do not meet the recognition criteria in IAS 37/CPC 25.

(In thousands of Reals, unless stated otherwise)

22. RELATED-PARTY BALANCES AND TRANSACTIONS
22.a) Transactions with subsidiaries, jointly controlled entities, affiliates, exclusive funds and otherrelated parties
· Consolidated
Consolidated
03/31/2026 12/31/2025
Associates Joint-ventures and Joint Operation Other related parties Total Associates Joint-ventures and Joint Operation Other related parties Total
Assets
Current Assets
Cash and cash equivalents 2,461,559 2,461,559 1,979,060 1,979,060
Trade receivables 6 73,382 17,010 90,392 73,045 24,254 97,299
Dividends receivable 9 23,016 140,368 54,362 217,746 19,477 2,187 54,362 76,026
Borrowings 9 2,944 2,944 4,147 4,147
Other receivables 9 2 1,829 1,831 2 1,829 1,831
96,398 160,324 2,517,750 2,774,472 92,522 30,590 2,035,251 2,158,363
Non-current Assets
Borrowings 9 6,275 1,657,647 1,663,922 6,024 2,131,858 2,137,882
Actuarial liabilities 9 54,946 54,946 53,328 53,328
6,275 1,657,647 54,946 1,718,868 6,024 2,131,858 53,328 2,191,210
102,673 1,817,971 2,572,696 4,493,340 98,546 2,162,448 2,088,579 4,349,573
Liabilities
Current Liabilities
Trade payables 21,874 769 22,643 19,493 171,345 864 191,702
Accounts payable 194,307 194,307 24,400 92,892 117,292
Dividends receivable 805,834 805,834
Advances from customers 8 188 196
Provision for consumption 25,841 25,841
21,882 957 1,000,141 1,022,980 19,493 221,586 93,756 334,835
21,882 957 1,000,141 1,022,980 19,493 221,586 93,756 334,835
Consolidated
03/31/2026 03/31/2025
Associates Joint-ventures and Joint Operation Other related parties Total Associates Joint-ventures and Joint Operation Other related parties Total
P & L
Sales 459,897 11,436 471,333 599,866 4,027 603,893
Cost and expenses (40,727) (527,462) (568,189) (43,337) (498,973) (39,256) (581,566)
Financial income (expenses)
Interest 28 250 57,082 1,215 58,547 617 48,261 4,096 52,974
Exchange rate variations and  monetary, net (33,110) (33,110)
Financial investments 50,772 50,772
Other income and expenses 76 76 53 1,422 1,475
419,420 (470,304) 12,651 (38,233) 557,146 (446,632) (16,076) 94,438
---

(In thousands of Reals, unless stated otherwise)

· Parent Company
Parent Company
03/31/2026 12/31/2025
Ref. Subsidiaries and associates Joint-ventures and Joint Operation Other related parties and exclusive funds Total Subsidiaries and associates Joint-ventures and Joint Operation Other related parties and exclusive funds Total
Assets
Current Assets
Cash and cash equivalents 121,343 121,343 418,642 418,642
Trade receivables 6 1,314,693 1,314,693 1,186,355 1,186,355
Dividends receivable 9 372,430 28,013 400,443 1,167,342 1,167,342
Borrowings 9 2,944 2,944 4,147 4,147
Other receivables 9 199,781 2 1,829 201,612 171,348 1,829 173,177
1,886,904 30,959 123,172 2,041,035 2,525,045 4,147 420,471 2,949,663
Non-current Assets
Borrowings 9 1,442,020 1,642,520 3,084,540 1,390,560 2,083,828 3,474,388
Actuarial asset 9 42,410 42,410 41,138 41,138
1,442,020 1,642,520 42,410 3,126,950 1,390,560 2,083,828 41,138 3,515,526
3,328,924 1,673,479 165,582 5,167,985 3,915,605 2,087,975 461,609 6,465,189
Liabilities
Current Liabilities
Intercompany Loans 13 237,570 237,570 193,654 193,654
Trade payables 1,591,371 51,589 1,642,960 47,150 47,798 412 95,360
Accounts payable 130,413 130,413 127,392 64,060 191,452
Provision for consumption 444,948 444,948 469,073 25,841 494,914
2,404,302 51,589 2,455,891 837,269 73,639 64,472 975,380
Non-current Liabilities
Intercompany Loans 13 9,042,985 9,042,985 9,807,672 9,807,672
Accounts payable 288,817 288,817 312,889 312,889
9,331,802 9,331,802 10,120,561 10,120,561
11,736,104 51,589 11,787,693 10,957,830 73,639 64,472 11,095,941
Parent Company
03/31/2026 03/31/2025
Subsidiaries and associates Joint-ventures and Joint Operation Other related parties and exclusive funds Total Subsidiaries and associates Joint-ventures and Joint Operation Other related parties and exclusive funds Total
Net revenue and cost
Sales 634,888 634,888 1,151,601 29 1,151,630
Cost and expenses (940,850) (135,787) (3,192) (1,079,829) (975,233) (125,641) (24,799) (1,125,673)
Financial income (expenses)
Interest 28 (16,457) 54,381 (21,494) 16,430 (10,724) 46,874 (2,605) 33,545
Exclusive funds 28 2,574 2,574
Financial investments ^(1)^ 50,772 50,772
Exchange rate variations and  monetary, net 546,088 546,088 872,030 872,030
Other operating income and expenses 20,085 25,917 1,272 47,274 47,855 53 1,158 49,066
243,754 (55,489) (23,414) 164,851 1,085,529 (78,685) 27,100 1,033,944

Consolidated and Controlling Information:

Receivables: These primarily relate to sales of the Parent Company’s steel products to related parties.

Dividends receivable: At the Parent Company, the balance consists primarily of dividends from CSN Cimentos Brasil S.A. in the amount of R$ 178,348 (R$ 178,348 as of December 31, 2025). In the consolidated financial statements, the balance consists primarily of dividends from MRS in the amount of R$ 140,368.

Loans (Assets):

Long-term: In the Consolidated Financial Statements, this refers primarily to loan agreements with Transnordestina Logística S.A. totaling R$1,525,381 (R$2,098,532 as of December 31, 2025), with an average interest rate of 125% to 130% of the CDI.

(In thousands of Reals, unless stated otherwise)

On March 31, 2026, Transnordestina Logística S.A. made a partial payment on the loan owed to CSN, in the amount of R$ 495,425, corresponding to R$ 464,995 net of taxes.

Dividends payable (Liabilities):

In the consolidated financial statements, a majority disposal of the balance of dividends receivable from CSN MINERAÇÃO from the related-party financial institution (Banco Fibra) in the amount of R$ 805,834, with a discount on the transaction of R$ 33,194. This transaction was settled in full on March 27, 2026.

22.b) Key Management Personnel

Key Management personnel with authority and responsibility for planning, directing and controlling the Company's activities include the members of the Board of Directors and statutory officers. Below is information on compensation and balances as of March 31, 2026 and March 31, 2025.

03/31/2026 03/31/2025
P&L
Short-term benefits for employees and officers 8,382 9,044
Post-employment benefits 187 222
8,569 9,266
22.c) Guarantees
--- ---
Currency Maturities Borrowings Tax foreclosure Others Total
--- --- --- --- --- --- --- --- --- --- ---
03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025 03/31/2026 12/31/2025
Transnordestina Logísitca R$ Up to 09/19/2056 and Indefinite 3,440,696 3,251,444 11,575 10,869 5,705 4,972 3,457,975 3,267,285
Subsidiaries R$ Up to 01/10/2028 and Indefinite 366,000 368,590 600 600 366,600 369,190
Total in R 3,806,696 3,620,034 11,575 10,869 6,305 5,572 3,824,575 3,636,475
CSN Inova Ventures US$ 01/28/2028 1,300,000 1,300,000 1,300,000 1,300,000
CSN Resources US$ Up to 04/08/2032 2,233,000 2,233,000 2,233,000 2,233,000
Total in US 3,533,000 3,533,000 3,533,000 3,533,000
Lusosider Aços Planos € Indefinite 75,000 75,000 75,000 75,000
Total em 75,000 75,000 75,000 75,000
Total in R 18,440,140 19,279,934 450,878 481,725 18,891,018 19,761,659
22,246,836 22,899,968 11,575 10,869 457,183 487,297 22,715,593 23,398,134

All values are in US Dollars.

23. EQUITY
23.a) Paid-in capital and authorized capital

The fully subscribed and paid-in share capital as of March 31, 2026 and December 31, 2025 is R$10,240,000, divided into 1,326,093,947 common and book-entry shares, with no par value. Each common share entitles the respective holder to a single vote in resolutions made at Annual General Meetings.

(In thousands of Reals, unless stated otherwise)

23.b) Authorized share capital

The Company's bylaws in force on March 31, 2026 define that the share capital may be increased to up to 2,400,000,000 shares, by decision of the Board of Directors, regardless of statutory reform.

23.c) Capital reserve

As of March 31, 2025 and December 31, 2025, the Company's capital reserve is R$32,720. These amounts refer to gain on the sale of the Company’s treasury shares.

23.d) Capital transaction

The balances reported as of March 31, 2025, and December 31, 2025, consist of gains on the sale of investments in subsidiaries, as well as treasury shares acquired by subsidiaries, amounting to R$ 1,949,438 and (R$ 2,248,080), respectively.

23.e) Legal reserve

It is constituted at the rate of 5% of the net income calculated in each fiscal period, before any other allocation, pursuant to art. 193 of Law no. 6.404/76, up to a limit of 20% of the share capital.

23.f) Ownership structure

As of March 31, 2026 and December 31, 2025, the shareholding composition is as follows:

03/31/2026 12/31/2025
Number of common shares % of total shares % of voting capital Number of common shares % of total shares % of voting capital
Vicunha Aços S.A. (*) 552,412,693 41.66% 41.66% 552,412,693 41.66% 41.66%
Rio Iaco Participações S.A. (*) 45,706,242 3.45% 3.45% 45,706,242 3.45% 3.45%
CFL Ana Participações S.A. 60,441,287 4.56% 4.56% 62,353,852 4.70% 4.70%
Avelina Participações S.A. 42,567,309 3.21% 3.21% 52,732,025 3.98% 3.98%
NYSE (ADRs) 340,389,596 25.67% 25.67% 320,979,296 24.20% 24.20%
Other shareholders 284,576,820 21.46% 21.46% 291,909,839 22.01% 22.01%
Outstanding shares 1,326,093,947 100.00% 100.00% 1,326,093,947 100.00% 100.00%

(*) Controlling group companies.

On July 11, 2025, CFL Participações S.A., the parent company of CFL Ana Participações S.A., in compliance with the provisions of Article 12, §6 of CVM Resolution 44/2021, notified the Company of the transfer of common shares issued by CSN from CFL Ana Participações S.A. to Avelina Participações S.A., a company also wholly controlled by CFL Participações S.A. CSN, in turn, notified the market of this transfer of a significant equity interest the following day, stating that CFL Participações S.A.’s stake now indirectly represents 9.99% of the share capital, as per the correspondence received.

(In thousands of Reals, unless stated otherwise)

23.g) Earnings/(Loss) per share

Earnings per share are shown below:

03/31/2026 03/31/2025
Common Shares
Loss for the period (555,023) (619,146)
Weighted average number of shares 1,326,093,947 1,326,093,947
Basic and diluted loss per share (0.41854) (0.46689)
23.h) Comprehensive income
--- ---

These are the accumulated actuarial adjustments to pension plans and the unrealized gains or losses on derivative financial instruments, such as the valuation adjustment for shares. The amount represents an accumulated gain of R$1,669,953 as of March 31, 2026 (R$782,078 as of December 31, 2025).

24. SHAREHOLDER COMPENSATION

As of March 31, 2026, the Company reported a net loss for the period of (R$ 555,023).

25. NET REVENUE FROM SALES

Net sales revenue is comprised as follows:

Consolidated Parent Company
03/31/2026 03/31/2025 03/31/2026 03/31/2025
Gross revenue
In Brazil 6,869,080 7,127,443 4,715,714 5,254,035
Abroad 5,282,370 5,468,013 82,481 325,629
12,151,450 12,595,456 4,798,195 5,579,664
Deductions
Sales returns, discounts and rebates (103,773) (171,754) (92,714) (92,575)
Taxes on sales (1,443,905) (1,516,073) (862,263) (996,765)
(1,547,678) (1,687,827) (954,977) (1,089,340)
Net revenue 10,603,772 10,907,629 3,843,218 4,490,324
---

(In thousands of Reals, unless stated otherwise)

26. EXPENSES BY NATURE
Consolidated Parent Company
--- --- --- --- ---
03/31/2026 03/31/2025 03/31/2026 03/31/2025
Raw materials and inputs (2,957,931) (3,107,442) (2,120,712) (2,216,916)
Outsourcing material ^(1)^ (681,260) (886,943)
Labor cost (1,354,049) (1,306,443) (486,870) (487,352)
Supplies (695,831) (847,851) (530,241) (683,431)
Maintenance cost (services and materials) (290,908) (362,237) (64,503) (129,374)
Outsourcing services (649,140) (708,049) (252,301) (387,710)
Freight (1,142,916) (1,108,919) (172,842) (196,218)
Depreciation, amortization and depletion (1,141,943) (972,008) (321,419) (337,183)
Others (504,993) (353,124) (9,766) (59,310)
(9,418,971) (9,653,016) (3,958,654) (4,497,494)
Classified as:
Cost of sales (8,081,068) (8,375,386) (3,696,417) (4,203,998)
Selling expenses (1,096,940) (1,060,232) (173,136) (205,282)
General and administrative expenses (240,963) (217,398) (89,101) (88,214)
(9,418,971) (9,653,016) (3,958,654) (4,497,494)

(1) Refers to the acquisition of third-party ores for blending.

Depreciation, amortization and depletion for the period were distributed as follows:

Consolidated Parent Company
03/31/2026 03/31/2025 03/31/2026 03/31/2025
Production costs (1,115,838) (947,302) (311,547) (325,585)
Selling expenses (13,707) (13,985) (3,003) (4,837)
General and administrative expenses (12,398) (10,721) (6,869) (6,761)
(1,141,943) (972,008) (321,419) (337,183)
Other operational ^(1)^ (13,213) (27,179) (10,433) (17,240)
(1,155,156) (999,187) (331,852) (354,423)

(1) They refer substantially to the depreciation of investment properties and scheduled shutdown for the renovation of Blast Furnace 2.

(In thousands of Reals, unless stated otherwise)

27. OTHER OPERATING (EXPENSES)/INCOME
Consolidated Parent Company
--- --- --- --- --- ---
Ref. 03/31/2026 03/31/2025 03/31/2026 03/31/2025
Other operating income
Receivables by indemnity 1,475 1,657 1,336 480
Rentals and leases 6,263 11,077 2,123 8,703
Contractual fines 1,325 9,607
Tax recuperation 26,127 14,725
Other revenues (1,307) 26,829 33,761 21,335
6,431 67,015 37,220 54,850
Other operating expenses
Taxes and fees (31,956) (38,320) (5,594) (12,527)
Expenses with environmental liabilities, net (10,037) (10,211) (1,197) 809
Net reversals/(expenses) on legal proceedings^^ (35,287) (153,946) (3,288) (15,075)
Contractual fines (54,908) (16,672)
Depreciation of investment properties, idle equipment and amortization of intangible assets 26 (13,213) (27,179) (10,433) (17,240)
Reversals/(Estimated write-offs or losses) in property, plant and equipment, intangible assets and investment properties, net of reversals 10.c, 11 and 12 (2,024) 12,886 (39,222) 14,177
(Losses)/Estimated reversals in inventories (187,688) 7,461 (155,929) 4,217
Idleness in stocks and paralyzed equipment (22,076) (47,272) (20,198) (44,097)
Studies and project engineering expenses (13,012) (17,636) (2,641) (9,162)
Healthcare plan expenses (23,176) (26,578) (21,728) (23,963)
Realized cash flow hedge 14.b (387,858) (152,882) (410,179) (185,856)
Pension plan expense (11,370) (14,497) (10,529) (13,724)
Reversals/(Expenses) on receivables 811 (3,066) 811 62
Other expenses (128,871) (41,185) (49,231) (22,673)
(920,665) (512,425) (746,030) (325,052)
Other operating income (expenses), net (914,234) (445,410) (708,810) (270,202)
---

(In thousands of Reals, unless stated otherwise)

28. FINANCIAL INCOME/(EXPENSE)
Consolidated Parent Company
--- --- --- --- --- ---
Ref. 03/31/2026 03/31/2025 03/31/2026 03/31/2025
Financial income
Related parties 22.a 82,265 53,342 103,677 77,097
Income from financial investments 170,822 416,859 53,938 94,805
Updated shares – Fair value through profit or loss 14.d 46,230 50,773 46,230 50,773
Dividends receivable 98 2,373 69 2,339
Interest and fines 20,912 12,482 10,841 7,077
Other income 7,247 19,228 4,921 16,261
327,574 555,057 219,676 248,352
Financial expenses
Borrowings and financing - foreign currency 13 (497,081) (599,036) (113,516) (118,505)
Borrowings and financing - local currency 13 (562,970) (501,744) (355,644) (332,374)
Capitalized interest 11 131,770 78,944 61,355 42,432
Interest of advances from customers (252,413) (349,919) (45,421) (34,925)
Related parties 22.a (23,718) (368) (87,247) (40,978)
Lease liabilities (25,990) (25,179) (829) (884)
Interest and fines (54,158) (24,282) (27,004) (16,078)
Interest on forfaiting operations (42,338) (44,340) (36,283) (44,340)
(-) Adjusted present value of trade payables (112,098) (123,723) (67,825) (82,398)
Commission, bank fees, guarantee and bank fees (70,213) (54,485) (18,533) (17,851)
PIS/COFINS over financial income (29,580) (21,407) (16,598) (9,298)
Other financial expenses (4,246) (34,869) 30,816 3,305
(1,543,035) (1,700,408) (676,729) (651,894)
Others financial items, net
Foreign exchange and monetary variation, net (58,610) (671,363) (176,477) (449,002)
Gains and (losses) on exchange derivatives (*) (34,108) (33,434) 21,396 68,005
Exchange rate fluctuations in iron ore 14.c 1,327 (199)
(91,391) (704,996) (155,081) (380,997)
(1,634,426) (2,405,404) (831,810) (1,032,891)
Financial income (expenses), net (1,306,852) (1,850,347) (612,134) (784,539)
(*) Statement of gains and (losses) on derivative transactions (note 14.c)
Exchange rate swap Real x Dollar (22,217) (115,921)
Interest rate swap CDI x IPCA (29,508) 21,450 (14,204) 6,968
Exchange rate swap CDI x Dollar 17,617 61,037 35,600 61,037
(34,108) (33,434) 21,396 68,005
29. SEGMENT INFORMATION

According to the Group's structure, the businesses are distributed and managed in five operating segments as follows:

· Steel operations

The Steel segment consolidates all operations related to the production, distribution and marketing of flat steel, long steel, metal packaging and galvanized steel, with operations in Brazil, United States, Portugal and Germany. The segment serves the construction, steel packaging for the chemical and food industries, home appliances, automotive, and OEM (engines and compressors) markets.

The Company's steel units produce hot-rolled, cold-rolled, galvanized, and pre-painted steel with great durability. It also produces tinplate, a raw material used in the production of packaging.

(In thousands of Reals, unless stated otherwise)

Operations in Brazil also involve the production and marketing of long steels, which consolidates the Company's position as a source of complete solutions for civil construction, complementing its portfolio of high value-added products in the steel chain.

Abroad, Lusosider, in Portugal, produces cold rolled and galvanized steels. CSN LLC, in the United States, serves the local market through the import and marketing of steel products. Stahlwerk Thüringen (SWT), located in Germany, produces long steel and is specialized in the production of steel profiles used in civil construction.

In March 2025, the Company acquired the company Gramperfil S.A. which is located in Portugal. This acquisition will complement local operations involving the production, importing, marketing and processing of metal profiles and accessories used in metallic and civil construction.

In November 2025, the Company acquired Galvacolor Jerez, S.L.U., which is located in Spain. Its activities consist of processing and sale of steel and steel products.

· Mining

Covers the mining and marketing activities of iron ore and tin.

Iron ore high quality operations are located in the Iron Quadrangle, in Minas Gerais, which, besides producing, also market iron ore purchased from third parties.

At the end of 2015, CSN and the Asian Consortium formalized a shareholders' agreement to combine assets related to iron ore operations and related logistics, forming a new company that concentrated the Group's main mining activities starting in December 2015. Based in this context, the new company, currently called CSN Mineração S.A., came to hold the lease of TECAR, as well as the Casa de Pedra mine and all Namisa shares, which was incorporated on December 31, 2015. CSN still holds 100% of Minérios Nacional which includes the mines of Fernandinho (operational), Cayman and Pedras Pretas (mineral resources), all located in Minas Gerais.

In addition, CSN controls Estanho de Rondônia S.A., a company with tin mining and smelting units in the state of Rondônia.

On October 7, 2022, CSN Mineração and CSN Energia completed the acquisition of the Quebra-Queixo Hydroelectric Plant, with an installed capacity of 120 MW, located in the city of Ipuaçu/SC, making CSN Mineração self-sufficient in electricity and strengthening its industrial competitiveness through greater cost predictability and energy generation from a 100% renewable source.

(In thousands of Reals, unless stated otherwise)

· Logistics

i. Railway

CSN has a stake in three railway companies: MRS Logística S.A., which manages Rede Ferroviária Federal S.A.’s former Southeast Network, Transnordestina Logística S.A. and FTL

  • Ferrovia Transnordestina Logística S.A. FTL - Ferrovia Transnordestina Logística S.A., which hold the concession for the former RFFSA Northeast Network in the states of Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco and Alagoas.

a) MRS

The rail transport services provided by MRS are fundamental to the supply of raw materials and the transport of final products. The entirety of the iron ore, coal and coke consumed at the Presidente Vargas Plant is transported by MRS, as well as part of the steel produced by CSN both for the domestic market and for export.

The southeastern Brazilian railway system, which spans 1,674 km of railway network, serves the industrial triangle of São Paulo - Rio de Janeiro - Minas Gerais in the Southeast region, connecting mines in Minas Gerais to ports in São Paulo and Rio de Janeiro, and to steel mills belonging to CSN, Companhia Siderúrgica Paulista (or Cosipa) and Gerdau Açominas. In addition to serving other customers, the line transports iron ore from the Casa de Pedra mine in Minas Gerais, as well as coke and coal from the Port of Itaguaí in Rio de Janeiro, to Volta Redonda, Rio de Janeiro, and products destined for export to the Ports of Itaguaí and Rio de Janeiro.

b) TLSA and FTL

TLSA and FTL hold the concession of the former RFFSA Northeast network. The northeastern railway system covers 4,238 km of railway network divided into two sections: i) Network I, which includes the sections of São Luiz - Mucuripe, Arrojado - Recife, Itabaiana - Cabedelo, Paula Cavalcante - Macau - and Propriá - Jorge Lins; and ii) Network II, which includes the sections of Missão Velha - Salgueiro, Salgueiro - Trindade, Trindade - Eliseu Martins and Missão Velha - Porto de Pecém.

In addition, it connects to the region’s major ports, offering a significant competitive advantage through opportunities for intermodal transport solutions and customized logistics projects.

ii. Port

The Company’s activities in port logistics sector were consolidated through the operation of the Sepetiba terminal, which was built after a port modernization law (Law 8.630/1993) allowing the transfer of port activities to the private sector was passed. The Sepetiba terminal offers the infrastructure required to meet all the needs of exporters, importers and shipowners. Its installed capacity exceeds that of most Brazilian terminals.

The Company's ongoing investment in terminal projects has consolidated the Itaguaí Port Complex as one of the most modern of its kind in Brazil.

(In thousands of Reals, unless stated otherwise)

iii. Land Transport

On April 1, 2025, CSN completed the acquisition of Estrela Comércio e Participações S.A., Grupo Estrela’s (“Grupo Estrela”) holding company. Founded in the 1970s to initially meet road transport needs, Grupo Estrela currently comprises an "Integrated Logistics System", which seeks integrate modes of transport, especially in road-rail operations and transport in the steel, mining, solid bulk, automotive and dry cargo sectors in general. The Tora Group’s services portfolio also includes terminal management, storage, operation of bonded warehouses, and production chain and light vehicle fleet management services, including the rental and resale of used vehicles.

Grupo Estrela maintains a national and international presence in the transport sector. The Group relies on more than 70 branches distributed throughout Brazil. It currently operates at four multimodal terminals located in the Southeast region of Brazil and a border terminal located in the city of Uruguaiana/RS. In the customs bonded warehouses segment, the company operates a terminal located in the city of Betim, Minas Gerais, which receives imported goods from the country’s major ports and airports.

In March 2024, the Estrela Group entered the light vehicle sector (fleet management, leasing, and pre-owned vehicle sales) through the acquisition of the Lokamig Group.

· Energy

CSN is one of the largest industrial consumers of electricity in Brazil. As energy is a fundamental input in its production process, the Company owns electric power generation assets, and with the acquisitions made in 2022, it achieved energy self-sufficiency before coming to operate in the sector as an electric power generation player through the commercialization of its surplus.

With the acquisitions, the CSN group now offers a portfolio of generation assets with a total installed capacity of 2,011 MW, which comprise the following assets:

1. Itá Hydroelectric Power Plant,<br>located in the state of Santa Catarina, in which CSN holds a 29.50% stake through the Itá Energética S.A SPE, with an installed<br>capacity equivalent to its 428 MW stake;
2. The Igarapava Hydroelectric Plant Consortium,<br>whose hydroelectric complex is located in Minas Gerais, in which CSN holds a 17.92% stake, with an installed capacity of 38 MW, equivalent<br>to its stake;
--- ---
3. Thermoelectric Cogeneration Center CTE#1,<br>CTE#2 and TRT – Top Recovery Turbine, operating at Presidente Vargas Plant with installed capacity of 10 MW, 235 MW and 22 MW respectively,<br>using industrial gases recirculated from steel production as fuel;
--- ---
4. Sacre II Small Hydroelectric Power Plant,<br>which is located in the state of Mato Grosso and has an installed capacity of 30 MW, of which CSN Cimentos Brasil S.A. holds full control<br>of the asset through indirect control of the Brasil Central Energia SPE;
--- ---
5. The Santa Ana Small Hydroelectric Plant,<br>located in the state of Santa Catarina, with an installed capacity of 6.3 MW, in which CSN Cimentos Brasil S.A. holds full ownership through<br>its direct control of the SPE Santa Ana Energética S.A.;
--- ---
---

(In thousands of Reals, unless stated otherwise)

6. The Quebra Queixo Hydroelectric Plant,<br>located in the state of Santa Catarina, with an installed capacity of 120 MW, in which CSN Mineração S.A. holds full ownership<br>through its direct control of the SPE Companhia Energética Chapecó (CEC);
7. The Cachoeira dos Macacos Small Hydroelectric<br>Plant, located in the state of Minas Gerais, with an installed capacity of 3.4 MW, in which CSN Cimentos Brasil S.A. holds full ownership<br>following its acquisition of LafargeHolcim (Brasil) S.A.;
--- ---
8. Companhia Estadual de Geração<br>de Energia Elétrica – CEEE-G, located in Rio Grande do Sul state, with a platform of 13 own Hydroelectric Plants, wind and<br>solar assets, plus minority participation in other ventures, reflecting an installed capacity of 1,119 MW.
--- ---
· Cement
--- ---

The Cement sector, for which operations are maintained through CSN Cimentos Brasil S.A., consolidates the production, sale and distribution of cement, aggregates and concrete. The slag used in plants located in the Southeast region is produced by the blast furnaces at the Presidente Vargas Plant itself, in Volta Redonda/RJ.

The Company has intensified its strategy of expanding to new regions, starting with the acquisition of Elizabeth Cimentos S.A. and Elizabeth Mineração Ltda. on August 31, 2021, which maintain operations in Brazil’s Northeast region and contribute 1.3 Mtpa of cement production capacity.

On September 6, 2022, relevant advances were made in the company’s cement-related business in terms of its capacity and geographic positioning through the acquisition of LafargeHolcim (Brasil) S.A. This asset will add a total of 11 million tons of cement production capacity, in addition to introducing new businesses areas to the Company’s current portfolio: Aggregates and Concrete. Taking all operations into account, CSN’s Cement segment is currently the second largest in Brazil in terms of effective production capacity, totaling 17 million tons per year.

Cement plants are located in the states of Minas Gerais, Rio de Janeiro, Espírito Santo, Bahia, Goiás and São Paulo. The production process occurs basically through grinding the main raw materials which include clinker, limestone, gypsum, and slag.

The company currently serves the cement market with a broad product portfolio suitable for both the technical segment and the distribution market, according to ABNT NBR 16697. The cement is sold in both bagged and bulk form.

In addition to the operations described above, CSN Cimentos Brasil S.A. owns two power generation assets acquired on June 30, 2022: the Santa Ana small hydroelectric plant, located in the municipality of Angelina/SC, with an installed capacity of 6.50 MW, and the Sacre II small hydroelectric plant, located in the municipality of Brasnorte/MT, with an installed capacity of 30 MW.

· Sales by Geographic Area

Sales by geographic area are determined based on customers' location. National sales on a consolidated basis are represented by revenues from customers located in Brazil and export sales represent revenues from customers located abroad.

(In thousands of Reals, unless stated otherwise)

Result by segment

For the purposes of preparing and presenting information by business segment, Management decided to maintain the proportional consolidation of the jointly controlled companies, as historically presented. For the purpose of consolidating the income statement, the values of these companies are eliminated in the column "Corporate expenses/elimination".

03/31/2026
P&L Ref. Steel Mining Logistics Energy Cement Corporate expenses/elimination Consolidated
Port Railroads Road transport
Net revenues 25 5,599,884 3,186,217 78,728 688,915 303,187 202,663 1,256,076 (711,898) 10,603,772
In Brazil 3,832,176 317,383 78,728 688,915 297,359 202,663 1,256,076 (1,250,570) 5,422,730
Abroad 1,767,708 2,868,834 5,828 538,672 5,181,042
Cost of sales and services 26 (5,245,407) (2,101,189) (61,973) (412,286) (268,537) (154,472) (823,395) 986,191 (8,081,068)
Gross profit 354,477 1,085,028 16,755 276,629 34,650 48,191 432,681 274,293 2,522,704
General and administrative expenses 26 (329,521) (77,088) (3,224) (64,278) (11,776) (8,749) (260,238) (583,029) (1,337,903)
Other operating income/(expenses), net 27 (289,661) (146,729) (3,134) 3,334 (1,896) 1,503 (29,626) (448,025) (914,234)
Equity in results of affiliated companies 10 23,777 23,777
Operating result before Financial Income and Taxes (264,705) 861,211 10,397 215,685 20,978 40,945 142,817 (732,984) 294,344
Sales by geographic area
Asia 264 2,791,754 538,688 3,330,706
North America 186,733 (16) 186,717
Latin America 2,274 5,828 8,102
Europe 1,578,437 77,080 1,655,517
Others
Foreign market 1,767,708 2,868,834 5,828 538,672 5,181,042
Domestic market 3,832,176 317,383 78,728 688,915 297,359 202,663 1,256,076 (1,250,570) 5,422,730
Total 5,599,884 3,186,217 78,728 688,915 303,187 202,663 1,256,076 (711,898) 10,603,772
03/31/2025
--- --- --- --- --- --- --- --- --- ---
Ref. Steel Mining Logistics Energy Cement Corporate expenses/elimination Consolidated
Port Railroads
Net revenues 25 6,107,126 3,432,139 85,591 685,107 178,447 1,101,713 (682,494) 10,907,629
In Brazil 4,217,207 429,119 85,591 685,107 178,447 1,101,709 (1,181,670) 5,515,510
Abroad 1,889,919 3,003,020 4 499,176 5,392,119
Cost of sales and services 26 (5,663,529) (2,283,635) (61,820) (420,316) (112,628) (807,393) 973,936 (8,375,386)
Gross profit 443,597 1,148,504 23,771 264,791 65,819 294,320 291,442 2,532,243
General and administrative expenses 26 (339,291) (66,214) (2,791) (62,599) (9,138) (261,493) (536,103) (1,277,630)
Other operating income/(expenses), net 27 (43,766) (45,345) (2,941) 16,623 (96,997) (30,220) (242,763) (445,410)
Equity in results of affiliated companies 10 78,434 78,434
Operating result before Financial Income and Taxes 60,540 1,036,945 18,039 218,815 (40,316) 2,607 (408,990) 887,637
Sales by geographic area
Asia 2,758,157 481,678 3,239,835
North America 445,536 445,536
Latin America 9,990 4 9,994
Europe 1,434,393 244,863 17,498 1,696,754
Others
Foreign market 1,889,919 3,003,020 4 499,176 5,392,119
Domestic market 4,217,207 429,119 85,591 685,107 178,447 1,101,709 (1,181,670) 5,515,511
Total 6,107,126 3,432,139 85,591 685,107 178,447 1,101,713 (682,494) 10,907,630
30. ADDITIONAL CASH FLOW INFORMATION

The following table provides additional information about transactions related to the statement of cash flows:

Consolidated Parent Company
Ref. 03/31/2026 03/31/2025 03/31/2026 03/31/2025
Income tax and social contribution paid 102,880 127,251
Addition to PP&E with interest capitalization 10 and 28 131,770 78,944 61,355 42,432
Remeasurement and addition – Right of use 11.b 25,896 74,156 1,041 1,944
Capitalization / acquisition of subsidiary without cash effect 37,180
260,546 317,531 62,396 44,376
---

(In thousands of Reals, unless stated otherwise)

31. OTHER COMPREHENSIVE INCOME
Consolidated Parent Company
03/31/2026 03/31/2025 03/31/2026 03/31/2025
Net income/(loss) (555,023) (731,580) (615,531) (619,146)
Other comprehensive income
Items that will not be subsequently reclassified to the statement of income
Actuarial gains/(losses) over pension plan of subsidiaries, net of taxes (6,138) 36 (6,138) 37
(6,138) 36 (6,138) 37
Items that could be subsequently reclassified to the statement of income
Cumulative translation adjustments for the year (212,235) (108,927) (212,235) (108,927)
(Loss)/gain cash flow hedge accounting, net of taxes 1,209,621 1,195,664 1,209,621 1,195,664
Cash flow hedge reclassified to income upon realization, net of taxes (270,718) 122,665 (270,718) 122,665
(Loss)/gain cash flow hedge accounting  –  “Platts”  from investments in subsidiaries, net of taxes 177,808 321,918 122,115 222,158
904,476 1,531,320 848,783 1,431,560
898,338 1,531,356 842,645 1,431,597
Comprehensive income for the year 343,315 799,776 227,114 812,451
Attributable to:
Earnings attributable to the controlling interests 227,114 812,451 227,114 812,451
Earnings attributable to the non-controlling interests 116,201 (12,675)
343,315 799,776 227,114 812,451
32. SUBSEQUENT EVENTS

ADVANCE FOR FUTURE CAPITAL INCREASE

On April 22, 2026, CSN contributed R$ 495,425 to Transnordestina Logística S.A. through an Advance Payment for a Future Capital Increase (AFAC).

SETTLEMENT OF FINANCIAL OBLIGATION

On April 17, 2026, the Company fully redeemed the 2026 Senior Unsecured Notes, which matured on that date, in the amount of US$189.9 million.

CASH INFLOWS TO THE COMPANY

On April 16, 2026, the Company began receiving the funds from the bridge loan it had secured, as disclosed in the Material Fact announcement dated March 20, 2026. The transaction, with a principal amount of US$1.2 billion, an option to increase the amount to up to US$1.4 billion, and a 5-year maturity, is intended to restructure short- and medium-term debt, refinance existing financial obligations, and pay expenses directly related to the transaction.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: May 26, 2026

COMPANHIA SIDERÚRGICA NACIONAL
By: /S/ Benjamin Steinbruch<br><br><br> <br>* * *
Benjamin Steinbruch<br><br><br> <br>Chief Executive Officer
--- ---
By: /S/ Antonio Marco Campos Rabello<br><br><br> <br>* * *
Antonio Marco Campos Rabello<br><br><br> <br>Chief Financial and Investor Relations Officer

FORWARD-LOOKING STATEMENTS

This press release may contain forward-looking statements. These statements are statements that are not historical facts, and are based on management's current view and estimates of future economic circumstances, industry conditions, company performance and financial results. The words "anticipates", "believes", "estimates", "expects", "plans" and similar expressions, as they relate to the company, are intended to identify forward-looking statements. Statements regarding the declaration or payment of dividends, the implementation of principal operating and financing strategies and capital expenditure plans, the direction of future operations and the factors or trends affecting financial condition, liquidity or results of operations are examples of forward-looking statements. Such statements reflect the current views of management and are subject to a number of risks and uncertainties. There is no guarantee that the expected events, trends or results will actually occur. The statements are based on many assumptions and factors, including general economic and market conditions, industry conditions, and operating factors. Any changes in such assumptions or factors could cause actual results to differ materially from current expectations.

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