China Oilfield Services Limited (the “Company”) announced on 22 May 2026 an updated final dividend for the year ended 31 December 2025, revising the Hong Kong-dollar payout amount, applicable exchange rate, payment date and related withholding-tax details.

The board has confirmed a final ordinary dividend of RMB 0.2825 per share. Based on an exchange rate of RMB 1:HKD 1.145103, shareholders whose holdings are registered on the Hong Kong share register will receive HKD 0.323492 per share.

Key timetable • Ex-dividend date: 9 June 2026 • Last day to lodge share transfers: 10 June 2026 (by 16:30) • Book-closure period: 11–16 June 2026 • Record date: 16 June 2026 • Payment date: 30 June 2026

Withholding tax framework • Non-resident enterprise shareholders: 10% withholding rate; if a relevant tax treaty sets a lower rate, the Company will still withhold at 10%. • Non-resident individual shareholders: standard 10% rate applies to Hong Kong, Macau and treaty jurisdictions with a 10% rate; treaties stipulating 10–20% attract the agreed effective rate; jurisdictions without treaties or with a 20% rate are subject to 20%. • Mainland individual investors holding H shares via Shanghai-Hong Kong or Shenzhen-Hong Kong Stock Connect: 20% withholding tax.

Computershare Hong Kong Investor Services Limited remains the share registrar, located at Shops 1712-1716, 17/F, Hopewell Centre, 183 Queen’s Road East, Wanchai, Hong Kong.