US regulators have approved China National Offshore Oil Corporation's (CNOOC's) US$15.1 billion bid to buy Nexen Inc, a deal that will be the biggest overseas takeover made by a Chinese company.

The approval from the Committee on Foreign Investment in the United States (CFIUS) means the last major hurdle was cleared, CNOOC, China's largest offshore oil producer, said in a statement issued yesterday.

Before this, the deal has won approvals from Nexen shareholders, local courts in Canada, the Canadian government, and the National Development and Reform Commission, China's economic planner.

Progresses of the deal with be publicized at a proper time, the statement said.

CNOOC said on January 28 that the closing date for the takeover would be postponed from January 31 to March 2, 2013.

The deal needed US approvals because Nexen, based in Calgary, Alberta, controlled assets in the Gulf of Mexico.

The Canadian stock market closed higher yesterday, lifted by energy stocks which were supported by higher oil prices and a gain in Nexen shares after the CNOOC-Nexen deal was approved by US regulators.