6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

_____________

FORM 6-K

Report of Foreign Issuer

Pursuant to Rule 13a-16 or 15d-16 of

the Securities and Exchange Act of 1934

For May 5, 2025

Commission file number: 1-13.396

Transportadora de Gas del Sur S.A.

Cecilia Grierson 355, Twenty sixth Floor

(1107), Capital Federal

Argentina

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

Form 20-F  X  Form 40-F

Indicate by check mark if registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): __

Indicate by check mark if registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): __

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 the Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes   No X

If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b):

City of Buenos Aires, May 5, 2025.

E-NOTA-20250505-58758

Messrs.

Comisión Nacional de Valores (Argentine Securities and Exchange Commission)

Bolsas y Mercados Argentinos S.A. (Argentine Stock Exchanges and Markets)

Bolsa de Comercio de Buenos Aires (Buenos Aires Stock Exchange)

Gerencia Técnica y de Valores Negociables (Technical and Negotiable Securities Management)

Mercado Abierto Electrónico S.A. (Open Electronic Market)

Re: Material Fact. Approval of five-year tariff revision . Approval of investment plans for the five-year period 2025-2030. Transitory t ariff a djustment.

Dear Sirs,

I am writing to you in my capacity as Head of Market Relations of Transportadora de Gas del Sur S.A. (“tgs”), to report that by means of Resolution no. 256/2025 dated April 29, 2025, issued by the Argentine Gas Regulatory Body (“ENARGAS”) -published in the Argentine Official Gazette on April 30, 2025- the ENARGAS resolved: (i) to approve tgs’ five-year tariff revision (“RQT”); (ii) to approve investment plans to be carried out by tgs in said five-year period; (iii) to approve tgs’ initial transitory tariff chart; (iv) to establish that the tariff increase resulting from RQT shall be paid in thirty one monthly and consecutive instalments and (v) to differ approval of tgs’ periodic tariff adjustment mechanism following intervention by the Executive Branch.

Yours sincerely,

Hernán Diego Flores Gómez

Head of Market Relations

SIGNATURES

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.

Transportadora de Gas del Sur S.A.

Date: May 5, 2025.