Philippines says to decide on Petron stake on Monday

MANILA, May 9 (Reuters) - The Philippines will announce next week whether it will exercise an option to buy Saudi Aramco's 40 percent stake in oil refiner Petron Corp (PCOR.PS), the president of the Philippine National Oil Co (PNOC) said on Friday.

"We will meet on Monday and announce our decision that day," PNOC President Antonio Cailao told Reuters. "Nothing is final yet."

PNOC has the first option to buy the stake and has until May 12 to decide whether or not it will exercise the option.

Petron, the Philippines' largest domestic refining company with a network of about 1,200 service stations, is 40 percent owned by PNOC and 40 percent by Aramco. The rest is held by individual investors.

Saudi Aramco, state oil firm of the world's biggest oil exporter, has received an offer of $550 million for its Petron stake from London-based investment fund Ashmore Group (ASHM.L).

The Philippine Daily Inquirer newspaper, quoting government sources, reported the government was not inclined to match Ashmore's offer and may sell its own 40 percent stake at a later date.

JG Summit Petrochemical Corp, controlled by the Gokongwei family, which also owns the country's second biggest airline Cebu Pacific, has offered to buy the government's shares in Petron for $579 million.

The offer from JG Summit Petrochemical Corp values Petron at 6.55 pesos per share, about a 9.2 percent premium to its closing price of 6 pesos on Friday.

Finance Secretary Margarito Teves has previously said the government was keeping its options open on the possible sale of government's stake in Petron.

Energy Secretary Angelo Reyes earlier said investment bank Morgan Stanley (MS.N) had also expressed interest to buy the Saudia Aramco stake. (Reporting by Karen Lema; Editing by Anshuman Daga)