CNOOC Limited (中国海洋石油有限公司) 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 since February 2001. It was listed on the New York Stock Exchange from 2001 to 2021. It was on the Toronto Stock Exchange between 2013 (following its acquisition of Nexen Inc) and 2021. It was admitted as a constituent stock of the Hang Seng Index in July 2001.