PetroChina Co.,Ltd. (857), a subsidiary of the state-backed China National Petroleum Corp., may buy the 40 percent of Canada’s MacKay River oil sands project that it doesn’t already own from Athabasca Oil Sands Corp. (ATH), the Calgary Herald said.

Athabasca said yesterday it’s close to receiving regulatory approval for the deal, which would trigger a 31-day option for the Calgary-based company to sell its stake or allow PetroChina to buy it, the newspaper said.

PetroChina would pay about $664 million to take over MacKay, which may produce 150,000 barrels of oil equivalent a day, the newspaper said.

PetroChina spokesman Mao Zefeng declined to comment when contacted by phone. A spokesman for Athabasca couldn’t be reached outside of office hours.