China's National Development and Reform Commission, the country's top economic planner, said Friday on its website that it approved CNOOC's acquisition of Canadian oil and gas company Nexen Inc in December.

On Dec 7, the Canadian government approved CNOOC's planned acquisition of Nexen, a major step for the company toward completing the largest foreign acquisition by a Chinese company.

The deal, which also involves Nexen's assets in the United States, the United Kingdom and other countries, is still waiting approval by those governments.

A CNOOC spokeswoman said last month that the deal is expected to be completed in the first quarter of this year.