CNOOC Limited will convene its 2025 Annual General Meeting (AGM) on 3 June 2026 at 10:00 a.m. at the Island Shangri-La Hotel in Hong Kong. Shareholders on the Hong Kong register as of 3 June are entitled to attend and vote; the register will be closed 29 May–3 June for administrative purposes.

Key resolutions to be put to vote include:

1. Financial Statements • Receipt and adoption of the audited consolidated results, directors’ report and auditors’ report for the year ended 31 December 2025 (released 9 April 2026 on HKEX).

2. Board Composition • Re-election of four directors: – Zhang Chuanjiang as Non-executive Director (current Chairman). – Huang Yongzhang as Executive Director (Vice Chairman, CEO, President). – Lin Boqiang as Independent Non-executive Director; annual fee: HK$0.95 million. – Li Shuk Yin Edwina as Independent Non-executive Director; annual fee: HK$1.17 million.

3. Remuneration • Authorisation for the Board to determine director remuneration schemes.

4. Auditor Mandate • Re-appointment of Ernst & Young Hua Ming LLP (domestic) and Ernst & Young (overseas) for FY2026 audits, with fee authority delegated to the Board. FY2025 audit fees totalled RMB73 million; 2026 pricing principles remain unchanged.

5. Shareholder Returns • Proposal to declare a final dividend of HK$0.55 (tax inclusive) per share for FY2025. The dividend will be paid in Hong Kong dollars for HK-listed shares; RMB-listed shares will receive the equivalent in Renminbi, translated at the PBoC’s average HKD/RMB central parity rate for the week preceding the AGM. • Ex-dividend period for Hong Kong shares: 15–18 June 2026; shareholders on record 18 June will qualify. • Authorisation for the Board to determine the 2026 interim dividend, capped at the company’s first-half net profit and subject to cash-flow and regulatory conditions.

Proxy forms for Hong Kong shareholders must be lodged with Computershare Hong Kong Investor Services by 4:00 p.m. on 1 June 2026 (36 hours before the AGM). Voting on all resolutions will be conducted by poll. No gifts, coupons or refreshments will be provided at the meeting.