CNOOC Limited has issued a notice convening its 2025 Annual General Meeting (AGM) for 10:00 a.m. on 3 June 2026 at Island Shangri-La, Hong Kong. Shareholders will consider nine ordinary resolutions encompassing financial reporting, board composition, remuneration, auditor appointments and dividend distribution.

Key agenda items 1. FY2025 reporting: Shareholders will receive and review the audited financial statements, the independent auditors’ report and the directors’ report for the year ended 31 December 2025. 2. Board re-elections: • Zhang Chuanjiang – Non-executive Director and current Board Chairman (initially appointed July 2025). • Huang Yongzhang – Executive Director, Vice Chairman, CEO and President (appointed March 2026). • Lin Boqiang – Independent Non-executive Director since September 2022. • Li Shuk Yin Edwina – Independent Non-executive Director, Chair of the Audit Committee since May 2023. Each appointment will run for 36 months with renewal possible on the same term. Lin and Li are entitled to annual director fees of HK$0.95 million and HK$1.17 million respectively; Zhang and Huang receive no director fees under current arrangements. 3. Directors’ remuneration: Authorisation for the Board to set remuneration schemes for all directors. 4. Auditor renewal: Re-appointment of Ernst & Young Hua Ming LLP (domestic) and Ernst & Young (overseas) for FY2026, with the Board authorised to determine their remuneration. 5. Dividend matters: • Proposal to declare a final dividend for FY2025 (amount to be determined at the meeting). • Authorisation for the Board to decide the 2026 interim dividend declaration plan.

Share registration timetable • AGM attendance and voting: Register of members for Hong Kong-listed shares will close from 29 May 2026 to 3 June 2026 inclusive. Share transfer documents must be lodged by 4:30 p.m. on 28 May 2026. • FY2025 final dividend entitlement (subject to approval): Register will close from 15 June 2026 to 18 June 2026 inclusive, with transfer documents due by 4:30 p.m. on 12 June 2026.

Proxy arrangements Shareholders may appoint one or more proxies to vote; forms must reach Computershare Hong Kong Investor Services at least 36 hours before the AGM.

As of 7 May 2026, the Board comprises four Non-executive Directors (including Chairman Zhang Chuanjiang), one Executive Director (Vice Chairman Huang Yongzhang) and three Independent Non-executive Directors (Qiu Zhi Zhong, Lin Boqiang, Li Shuk Yin Edwina).