OSHAWA, Ont. -- Stephen Harper is warning Canadians not to jump to conclusions about whether the federal government supports a $15-billion Chinese bid for oil giant Nexen Inc. (TSX:NXY)

Harper is telling a news conference in Oshawa, Ont., that the bid will be carefully scrutinized and assessed on the basis of whether it's of net benefit to Canada, as the law requires.

He says nothing has been decided as of yet and nobody should prejudge the outcome of the Competition Bureau's review.

If the bid by China National Offshore Oil Co. is successful, it would be China's largest-ever overseas acquisition.

The friendly bid also promises to maintain Nexen's Calgary base and keep all of its current employees and management.

Nexen has faced numerous challenges over the past few years, including the troubled launch of its Long Lake oilsands project in northern Alberta and recent second-quarter profits that fell nearly 57 per cent thanks to a failed well in the Gulf of Mexico.