Sinopec of China has agreed to acquire a 10% stake in a prime deepwater block offshore Angola from Marathon Oil for US $1.52 billion.

Wholly-owned subsidiary Sonangol Sinopec International Ltd. (SSI) will acquire Marathon International Oil Angola Block 31 Ltd.’s 10% stake in Block 31, it said in a statement. The block is operated by BP and has estimated proved and probable reserves of 533 MMbbl, according to Sinopec, which added that it would hold a stake of 15% in the block when the transaction was completed. Marathon confirmed it had entered into a definitive agreement to sell the 10% interest in the Production Sharing Contract and Joint Operating Agreement to SSI.

The companies anticipate closing the transaction in the fourth quarter of 2013, with an effective date of 1 January, 2013. The deal is subject to approval by the Chinese and Angolan governments, with the latter’s stateowned Sonangol also having first right of refusal on the block. It blocked a $1.3 billion deal to sell a 20% stake in Angola’s Block 32 to China’s CNOOC and Sinopec by exercising a similar option in 2009.

BP operates Block 31 with a 26.67% interest, with the other partners being Sonangol E.P. (25%), Sonangol P&P (20%), Statoil Angola (13.33%) and Sonangol-Sinopec joint venture SSI 31 Ltd. (5%).

Block 31 contains the producing PSVM development, one of the largest FPSO and subsea developments in the world, which came onstream late last year.