A Canadian court has approved China National Petroleum Corp's (CNPC) $4.2bn (£2.4bn) takeover of Alberta-based oil firm PetroKazakhstan.
China's rapid economic growth is fuelling its demand for oil supplies
PetroKazakhstan is headquartered in Canada, but its operations are all based in the central Asian republic of Kazakhstan.
The Canadian court turned down an attempt by Russian oil firm and rival suitor Lukoil to block the sale.
Lukoil said it should have first rights as it co-owns a PetroKazakhstan unit.
The Russian company has a 50% stake in Turgai Petroleum, which holds about 20% of PetroKazakhstan's reserves.
Lukoil had offered to match CNPC's $4.2bn offer, but the Canadian court turned down its appeal.
PetroKazakhstan and state-owned CNPC said they now intended to close the deal later on Wednesday.
However some analysts said Lukoil may yet make another appeal, this time to the Stockholm Arbitration Court.
The Kazakhstan government has backed the sale of PetroKazakhstan, and will itself now pay $1.4bn for a 33% stake as part of the deal with CNPC.
China has been working hard over the last year to increase its access to the global oil stocks it needs to consume, as its economy continues to grow at breakneck speed.
It has already started work on a pipeline from Kazakhstan.
But a bid by Chinese oil firm CNOOC for US rival Unocal failed back in the summer after strong opposition from American politicians.