Davis Polk & Wardwell and Beijing-based Commerce & Finance Law Offices have advised one of China’s largest oil companies on a $2 billion debt issue on the Hong Kong Stock Exchange.

China National Offshore Oil Corp. Ltd. has issued two tranches of debt: a $1.5 billion offering of 10-year notes, and 30-year bonds worth $500 million. The state-owned oil company has guaranteed the securities, which are being issued by a subsidiary.