Cnooc Said to Cede Control of Nexen’s U.S. Gulf Assets

Cnooc Ltd., China’s largest offshore oil and natural gas producer, was barred from controlling Gulf of Mexico oilfields under U.S. terms for its $15.1 billion takeover of Nexen Inc., people familiar with the matter said.

In its purchase of Calgary-based Nexen, Cnooc acquired about 200 deep-water leases in the Gulf with reserves equivalent to about 205 million barrels of oil, one of the largest holdings in the Gulf, according to Nexen’s website. The state-owned Chinese oil explorer surrendered operating control of those assets to quell U.S. national security concerns, said two people familiar with the agreement who asked not to be named because the terms aren’t public.