BP has agreed to sell its 15% interest in Ethylene Malaysia (EMSB) and 60% interest in Polyethylene Malaysia (PEMSB) to Petronas.
Under the agreement, Petronas will pay $363m including a balance sheet adjustment of $13m, and the repayment of a shareholder loan worth $53m.
BP said Petronas will also pay an EMSB pre-closing dividend of $48m to BP under the transaction, which is expected to be completed by the end of 2010.
EMSB has an annual ethylene production capacity of 440,000t.
PEMSB, which shares a 60% and 40% interest of BP and Petronas respectively, has an annual polyethylene capacity of 318,000t.