The voluntary submission was made to the Committee on Foreign Investment in the United States, Peter Hunt, a CNOOC spokesman, said in a phone interview, declining to say when the company made the filing.
The committee, known as CFIUS and chaired by Treasury Secretary Timothy Geithner, reviews foreign takeovers of U.S. companies on national security grounds.
Cnooc, owned by the Chinese government and based in Beijing, agreed July 23 to pay $15.1 billion for Nexen, a Calgary-based company that operates in the U.S. portion of the Gulf of Mexico.
A Nexen takeover would mark the first time a Chinese company would be the operator of U.S. leases in those waters instead of a minority stakeholder. Nexen also has operations in Canada’s oil sands, the U.K. North Sea and Nigeria.
Cnooc and Nexen said in a July 24 filing with the U.S. Securities and Exchange Commission that they intend to put the deal to CFIUS for review.
CNOOC applied for approval from the Canadian government on Aug. 29.
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