China National Offshore Oil Corporation
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 and in New York 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.