BEIJING -- US regulators have approved China National Offshore Oil Corporation's $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 means the last major hurdle was cleared, CNOOC, China's largest offshore oil producer, said in a statement issued on Tuesday.

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 Jan 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.

Timeline:

Nov 30, 2012 Nexen deal resubmission part of approval process 

Nov 28, 2012 CNOOC, Nexen reapply for US deal approval

Nov 10, 2012 Nexen deal approval 'in sight' 

Nov 5, 2012 CNOOC's Nexen bid review extends another 30 days

Oct 12, 2012 Canada extends review of CNOOC's Nexen bid

Oct 9, 2012 CNOOC Nexen bid 'net benefits' Canada and China

Aug 27, 2012 Nexen schedules vote on CNOOC's $15.1b offer

Aug 22, 2012 CNOOC pushes ahead with Nexen acquisition

July 27, 2 CNOOC to stick to market procedures in Nexen deal

July 25, 2012 CNOOC's Nexen deal expected to open two-way street