BEIJING -- China Petrochemical Corp, or Sinopec Group, the country's top oil refiner, on Monday announced that it has signed a deal with US oil giant Marathon Oil Corp to buy its oil and gas field in Angola for $1.52 billion.

According to the deal, Sinopec Group will purchase Marathon's 10 percent stake on the Angolan Block 31 field through its subsidiary Sonangal Sinopec International Ltd.

The Angolan Block 31 field, operated by British Petroleum (BP), has estimated proven and probable (2p) oil reserves of 533 million barrels, Sinopec said.

Together with the 5 percent stake in Block 31 field Sinopec purchased from French oil major Total in 2011, Sinopec's stake in the block will reach 15 percent upon the completion of the Marathon deal.

The deal is subject to approval by the Chinese and Angolan governments.