LYB

Prior to the beginning of the year, the reporting person elected to receive common stock in lieu of cash for her annual retainer, which is paid in quarterly installments. The number of shares issued was calculated based on $68.99, which is the average of the daily closing prices of the issuer's shares over the applicable quarter.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

Prior to the beginning of the year, the reporting person elected to receive common stock in lieu of cash for her annual retainer, which is paid in quarterly installments. The number of shares issued was calculated based on $68.99, which is the average of the daily closing prices of the issuer's shares over the applicable quarter.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 540 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 565 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 639 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 521 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 593 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 540 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 5,577 shares. 575 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 4,437 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 708 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 689 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 1,410 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

On May 22, 2026 the reporting person's restricted stock units automatically vested 2,917 shares. 1,247 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 2,321 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 10,014 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 5,577 that vest on May 22, 2026. The 4,437 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

Includes 5,238 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan, including 2,917 that vest on May 22, 2026. The 2,321 RSUs reported on this Form 4 vest on May 21, 2027.

This transaction was executed in multiple trades at prices ranging from $74.13 USD to $74.21 USD. The price reported above reflects the weighted-average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

Includes 32,627 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 3,218 granted on February 22, 2024 that vest on February 22, 2027; 4,103 granted on February 27, 2025 that vest on February 27, 2027; 4,103 granted on February 27, 2025 that vest on February 27, 2028 and 21,203 granted on February 28, 2026 of which: 7,069 vest on February 28, 2027, 7,067 vest on February 28, 2028 and 7,067 vest on February 28, 2029.

On April 15, 2026 the reporting person's restricted stock units automatically vested 163 shares. 40 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Includes 5,828 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 237 granted on February 22, 2024 that vest on February 22, 2027; 623 granted on October 15, 2024 that vest on October 15, 2026; 305 granted on February 27, 2025 that vest on February 27, 2027; 305 granted on February 27, 2025 that vest on February 27, 2028; 163 granted on April 15, 2025 that vest on April 15, 2027; 163 granted on April 15, 2025 that vest on April 15, 2028; 1,344 granted on February 28, 2026 that vest on February 28, 2027, 1,344 granted on February 28, 2026 that vest on February 28, 2028 and 1,344 granted on February 28, 2026 that vest on February 28, 2029.

ESPP purchase of 142.1216 shares for $38.97 per share were allocated on March 31, 2026.

On April 15, 2026 the reporting person's restricted stock units automatically vested 182 shares. 45 shares were withheld by the issuer to satisfy the issuer's tax withholding obligations.

Represents 26,216 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 242 granted on February 22, 2024 that vest on February 22, 2027; 182 granted on April 15, 2024 that vest on April 15, 2027; 2,817 granted on February 27, 2025 that vest on February 27, 2027; 2,817 granted on February 27, 2025 that vest on February 27, 2028; 6,720 granted on February 28, 2026 that vest on February 28, 2027, 6,719 granted on February 28, 2026 that vest on February 28, 2028 and 6,719 granted on February 28, 2026 that vest on February 28, 2029.

Includes 2,917 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 22, 2026.

Prior to the beginning of the year, the reporting person elected to receive common stock in lieu of cash for her annual retainer, which is paid in quarterly installments. The number of shares issued was calculated based on $59.31, which is the average of the daily closing prices of the issuer's shares over the applicable quarter.

Includes 2,917 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 22, 2026.

Prior to the beginning of the year, the reporting person elected to receive common stock in lieu of cash for her annual retainer, which is paid in quarterly installments. The number of shares issued was calculated based on $59.31, which is the average of the daily closing prices of the issuer's shares over the applicable quarter.

Includes 2,917 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 22, 2026.

Includes 2,917 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan that vest on May 22, 2026.

The price reported in Column 4 is a weighted average sales price of the ordinary shares. The ordinary shares were sold in multiple transactions ranging from $68.72 to $69.19 inclusive. The reporting persons undertake to provide to LyondellBasell Industries N.V., any security holder of LyondellBasell Industries N.V., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of ordinary shares sold at each separate price within the ranges set forth in this footnote to this Form 4.

Each of the reporting persons (other than the direct holder) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this Form shall not be construed as an admission that any such reporting person is the beneficial owner of any such securities.

Because of their relationships with the other reporting persons, each of Access Industries Holdings LLC, Access Industries, LLC and Access Industries Management, LLC may be deemed to beneficially own the ordinary shares held directly by AI Altep Investments LLC (formerly AI New Holdings LLC) and AI Chemical Holdings LLC (formerly, AI New Holdings 2 LLC) ("AICH"). Each of the reporting persons, and each of their affiliated entities and the officers, partners, members, and managers thereof, disclaims beneficial ownership of the ordinary shares held directly by each of AI Altep Investments LLC and AICH.

The securities reported are held directly by AICH and may be deemed to be indirectly beneficially owned by Access Industries Management, LLC, Access Industries Holdings LLC and Len Blavatnik because Mr. Blavatnik controls Access Industries Management, LLC, Access Industries Holdings LLC owns a majority of the outstanding voting interests in RSB 2 Limited which is the sole member of AICH, and Access Industries Management, LLC controls AICH and Access Industries Holdings LLC.

The price reported in Column 4 is a weighted average sales price of the ordinary shares. The ordinary shares were sold in multiple transactions ranging from $67.72 to $68.715 inclusive. The reporting persons undertake to provide to LyondellBasell Industries N.V., any security holder of LyondellBasell Industries N.V., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of ordinary shares sold at each separate price within the ranges set forth in this footnote to this Form 4.

Each of the reporting persons (other than the direct holder) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this Form shall not be construed as an admission that any such reporting person is the beneficial owner of any such securities.

The securities reported are held directly by AI Investments Holdings LLC ("AIIH") and may be deemed to be indirectly beneficially owned by Access Industries, LLC, Access Industries Holdings LLC, Access Industries Management, LLC and Len Blavatnik because Access Industries Holdings LLC controls a majority of the outstanding voting interests in AIIH, Access Industries, LLC controls a majority of the outstanding voting interests in Access Industries Holdings LLC, Access Industries Management, LLC controls Access Industries, LLC, Access Industries Holdings LLC and AIIH, and Mr. Blavatnik controls Access Industries Management, LLC and a majority of the outstanding voting interests in Access Industries, LLC.

These shares were donated by Access Industries Core Holdings LLC (formerly AIPH Holdings LLC) ("AICH") for no consideration as a charitable contribution.

Each of the reporting persons (other than the direct holder) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this Form shall not be construed as an admission that any such reporting person is the beneficial owner of any such securities.

The securities reported are held directly by AICH and may be deemed to be indirectly beneficially owned by Access Industries, LLC, Access Industries Holdings LLC, Access Industries Management, LLC and Len Blavatnik because Access Industries Holdings LLC controls a majority of the outstanding voting interests in AICH, Access Industries, LLC controls a majority of the outstanding voting interests in Access Industries Holdings LLC, Access Industries Management, LLC controls Access Industries, LLC, Access Industries Holdings LLC and AICH and Mr. Blavatnik controls Access Industries Management, LLC and a majority of the outstanding voting interests in Access Industries, LLC.

The price reported in Column 4 is a weighted average sales price of the ordinary shares. The ordinary shares were sold in multiple transactions ranging from $66.72 to $67.7193 inclusive. The reporting persons undertake to provide to LyondellBasell Industries N.V., any security holder of LyondellBasell Industries N.V., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of ordinary shares sold at each separate price within the ranges set forth in this footnote to this Form 4.

Each of the reporting persons (other than the direct holder) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this Form shall not be construed as an admission that any such reporting person is the beneficial owner of any such securities.

Because of their relationships with the other reporting persons, each of Access Industries Holdings LLC, Access Industries, LLC and Access Industries Management, LLC may be deemed to beneficially own the ordinary shares held directly by AI Altep Investments LLC (formerly AI New Holdings LLC) and AI Chemical Holdings LLC (formerly, AI New Holdings 2 LLC) ("AICH"). Each of the reporting persons, and each of their affiliated entities and the officers, partners, members, and managers thereof, disclaims beneficial ownership of the ordinary shares held directly by each of AI Altep Investments LLC and AICH.

The securities reported are held directly by AICH and may be deemed to be indirectly beneficially owned by Access Industries Management, LLC, Access Industries Holdings LLC and Len Blavatnik because Mr. Blavatnik controls Access Industries Management, LLC, Access Industries Holdings LLC owns a majority of the outstanding voting interests in RSB 2 Limited which is the sole member of AICH, and Access Industries Management, LLC controls AICH and Access Industries Holdings LLC.

The price reported in Column 4 is a weighted average sales price of the ordinary shares. The ordinary shares were sold in multiple transactions ranging from $68.72 to $69.19 inclusive. The reporting persons undertake to provide to LyondellBasell Industries N.V., any security holder of LyondellBasell Industries N.V., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of ordinary shares sold at each separate price within the ranges set forth in this footnote to this Form 4.

Each of the reporting persons (other than the direct holder) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this Form shall not be construed as an admission that any such reporting person is the beneficial owner of any such securities.

The securities reported are held directly by AI Investments Holdings LLC ("AIIH") and may be deemed to be indirectly beneficially owned by Access Industries, LLC, Access Industries Holdings LLC, Access Industries Management, LLC and Len Blavatnik because Access Industries Holdings LLC controls a majority of the outstanding voting interests in AIIH, Access Industries, LLC controls a majority of the outstanding voting interests in Access Industries Holdings LLC, Access Industries Management, LLC controls Access Industries, LLC, Access Industries Holdings LLC and AIIH, and Mr. Blavatnik controls Access Industries Management, LLC and a majority of the outstanding voting interests in Access Industries, LLC.

The price reported in Column 4 is a weighted average sales price of the ordinary shares. The ordinary shares were sold in multiple transactions ranging from $67.72 to $68.715 inclusive. The reporting persons undertake to provide to LyondellBasell Industries N.V., any security holder of LyondellBasell Industries N.V., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of ordinary shares sold at each separate price within the ranges set forth in this footnote to this Form 4.

Each of the reporting persons (other than the direct holder) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this Form shall not be construed as an admission that any such reporting person is the beneficial owner of any such securities.

Because of their relationships with the other reporting persons, each of Access Industries Holdings LLC, Access Industries, LLC and Access Industries Management, LLC may be deemed to beneficially own the ordinary shares held directly by AI Altep Investments LLC (formerly AI New Holdings LLC) and AI Chemical Holdings LLC (formerly, AI New Holdings 2 LLC) ("AICH"). Each of the reporting persons, and each of their affiliated entities and the officers, partners, members, and managers thereof, disclaims beneficial ownership of the ordinary shares held directly by each of AI Altep Investments LLC and AICH.

The securities reported are held directly by AICH and may be deemed to be indirectly beneficially owned by Access Industries Management, LLC, Access Industries Holdings LLC and Len Blavatnik because Mr. Blavatnik controls Access Industries Management, LLC, Access Industries Holdings LLC owns a majority of the outstanding voting interests in RSB 2 Limited which is the sole member of AICH, and Access Industries Management, LLC controls AICH and Access Industries Holdings LLC.

The price reported in Column 4 is a weighted average sales price of the ordinary shares. The ordinary shares were sold in multiple transactions ranging from $66.72 to $67.7193 inclusive. The reporting persons undertake to provide to LyondellBasell Industries N.V., any security holder of LyondellBasell Industries N.V., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of ordinary shares sold at each separate price within the ranges set forth in this footnote to this Form 4.

Each of the reporting persons (other than the direct holder) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this Form shall not be construed as an admission that any such reporting person is the beneficial owner of any such securities.

The securities reported are held directly by AI Investments Holdings LLC ("AIIH") and may be deemed to be indirectly beneficially owned by Access Industries, LLC, Access Industries Holdings LLC, Access Industries Management, LLC and Len Blavatnik because Access Industries Holdings LLC controls a majority of the outstanding voting interests in AIIH, Access Industries, LLC controls a majority of the outstanding voting interests in Access Industries Holdings LLC, Access Industries Management, LLC controls Access Industries, LLC, Access Industries Holdings LLC and AIIH, and Mr. Blavatnik controls Access Industries Management, LLC and a majority of the outstanding voting interests in Access Industries, LLC.

Includes 32,627 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 3,218 granted on February 22, 2024 that vest on February 22, 2027; 4,103 granted on February 27, 2025 that vest on February 27, 2027 and 4,103 granted on February 27, 2025 that vest on February 27, 2028. The 21,203 RSUs reported on this Form 4 vest as follows: 7,069 vest on February 28, 2027, 7,067 vest on February 28, 2028 and 7,067 vest on February 28, 2029.

Includes 9,531 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 2,205 granted on February 22, 2024 of which 735 were deferred on February 22, 2025, 735 were deferred on February 22, 2026; 735 vest on February 22, 2027; 1,022 granted on February 27, 2025 that vest on February 27, 2027 and 1,022 granted on February 27, 2025 that vest on February 27, 2028. The 5,282 RSUs reported on this Form 4 vest as follows: 1,762 vest on February 28, 2027, 1,760 vest on February 28, 2028 and 1,760 vest on February 28, 2029.

Includes 18,103 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 1,696 granted on February 22, 2024 that vest on February 22, 2027; 2,099 granted on February 27, 2025 that vest on February 27, 2027 and 2,099 granted on February 27, 2025 that vest on February 27, 2028. The 12,209 RSUs reported on this Form 4 vest as follows: 4,071 vest on February 28, 2027, 4,069 vest on February 28, 2028 and 4,069 vest on February 28, 2029.

Includes 152,099 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 15,406 granted on February 22, 2024 that vest on February 22, 2027; 19,072 granted on February 27, 2025 that vest on February 27, 2027 and 19,072 granted on February 27, 2025 vest on February 27, 2028. The 98,549 RSUs reported on this Form 4 vest as follows: 32,851 vest on February 28, 2027, 32,849 vest on February 28, 2028 and 32,849 vest on February 28, 2029.

Includes 24,618 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 2,428 granted on February 22, 2024 that vest on February 22, 2027; 3,096 granted on February 27, 2025 that vest on February 27, 2027 and 3,096 granted on February 27, 2025 that vest on February 27, 2028. The 15,998 RSUs reported on this Form 4 vest as follows: 5,334 vest on February 28, 2027, 5,332 vest on February 28, 2028 and 5,332 vest on February 28, 2029.

Represents 26,398 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 242 granted on February 22, 2024 that vest on February 22, 2027; 182 granted on April 15, 2024 that vest on April 15, 2026; 182 granted on April 15, 2024 that vest on April 15, 2027; 2,817 granted on February 27, 2025 that vest on February 27, 2027 and 2,817 granted on February 27, 2025 that vest on February 27, 2028. The 20,158 RSUs reported on this Form 4 vest as follows: 6,720 vest on February 28, 2027, 6,719 vest on February 28, 2028 and 6,719 vest on February 28, 2029.

Includes 5,991 restricted stock units ("RSUs") granted pursuant to the issuer's long-term incentive plan: 237 granted on February 22, 2024 that vest on February 22, 2027; 623 granted on October 15, 2024 that vest on October 15, 2026; 305 granted on February 27, 2025 that vest on February 27, 2027; 305 granted on February 27, 2025 that vest on February 27, 2028 and 489 granted on April 15, 2025 of which 163 vest on April 15, 2026, 163 vest on April 15, 2027 and 163 vest on April 15, 2028. The 4,032 RSUs reported on this Form 4 vest as follows: 1,344 vest on February 28, 2027, 1,344 vest on February 28, 2028 and 1,344 vest on February 28, 2029.