China National Petroleum Corp reached an agreement with PetroKazakhstan Inc to buy the Canadian-registered company for US$4.18 billion.

The nation's largest oil and gas producer, China National Petroleum Corp (CNPC), Monday reached an initial agreement with PetroKazakhstan Inc to buy the Canadian-registered company for US$4.18 billion, topping the bid from an Indian rival.

CNPC, the State-owned parent of Hong Kong-listed PetroChina, and PK have entered into an Arrangement Agreement whereby the Chinese oil firm will pay US$55 a share, or 21 per cent more than its closing share price on Friday, PetroKazakhstan said in a statement Monday.