CNOOC Limited announced an updated timetable and tax details for its FY2025 final dividend of HKD 0.55 per share.

Key Dates • Shareholders’ approval: 03 June 2026 • Ex-dividend date: 11 June 2026 • Deadline to lodge share transfers: 16:30 on 12 June 2026 • Book-closure period: 15 – 18 June 2026 • Record date: 18 June 2026 • Payment date: 10 July 2026

Dividend Terms • Type: Final, ordinary • Amount: HKD 0.55 per share, payable in Hong Kong dollars

Withholding-Tax Arrangement • CNOOC is classified as a PRC resident enterprise and must withhold 10% enterprise income tax on the dividend distributed to non-resident enterprise shareholders recorded on 18 June 2026. • Individual shareholders on the same date are exempt from withholding. • Shanghai-Hong Kong and Shenzhen-Hong Kong Stock Connect investors, whose shares are held through HKSCC Nominees Limited, will receive the dividend net of the 10% tax. • Shareholders entitled to a reduced rate or exemption must submit relevant tax documentation to Computershare Hong Kong Investor Services by 16:30 on 12 June 2026.

Registry Details Computershare Hong Kong Investor Services Limited, Shops 1712-1716, 17/F, Hopewell Centre, 183 Queen’s Road East, Wan Chai, Hong Kong, will act as the share registrar.

Additional Information Details for holders of the company’s RMB-denominated shares are provided in a separate announcement on the websites of the Shanghai Stock Exchange and CNOOC.