PetroChina Co, the country's largest oil and gas producer, has agreed to pay C$1.9 billion ($1.7 billion) for a stake in two oil sands projects in Canada to tap the rich deposits in the country.

Beijing-based PetroChina has signed initial agreements with Athabasca Oil Sands Corp (AOSC) to take a 60 percent stake in the Canadian company's MacKay River and Dover oil sands projects. The projects contain approximately 5 billion barrels of bitumen, AOSC said in a statement late Monday.

Analysts said the deal, which is China's largest investment in Canada's oil sands, is in line with its need to diversify energy supplies to enhance energy security.