CNOOC Limited is China's largest producer of offshore crude oil and natural gas, noted as such in 2010. It is a major subsidiary of China National Offshore Oil Corporation (CNOOC) and has been listed in Hong Kong SEHK: 883 and in New York NYSE: CEO since February 2001. It was admitted as a constituent stock of the Hang Seng Index in July 2001. In September 2013 it was listed on the Toronto Stock Exchange following its acquisition of Canadian oil and gas company Nexen Inc.
China National Offshore Oil Corporation or CNOOC, is a state-owned enterprise based in Beijing, capital of China. In order to float most of its assets in Hong Kong stock exchange, a special purpose vehicle was incorporated in Hong Kong as an intermediate holding company, in order to transfer the control of some subsidiaries to the company. Thus, it was considered as a red chip company of the exchange, due to its government background but incorporated outside mainland China. As of 31 March 2020, the company had a market capitalization of HK$363 billion.
Its core domestic operation areas are in Bohai, the South China Sea, and the East China Sea. Internationally, it has oil and gas assets in Asia, Africa, North America, South America, and Oceania.
As of December 31, 2011, the CNOOC Limited owned net proven reserves of approximately 3.19 billion barrel of oil equivalent (BOE), and its average daily net production was 909,000 BOE.