China's offshore oil and gas major CNOOC Ltd expects Brent crude oil prices to average $30 to $40 per barrel this year, a company executive said on Wednesday.

The state-controlled firm will produce at the lowest level in high-cost projects such as oil sands in Canada and shale gas operations in the United States.

(Reporting by Muyu Xu in Beijing and Chen Aizhu in Singapore; editing by Jason Neely)