MANILA, Philippines?(UPDATE) Major oil firms Petron Corp. and Chevron Phil. Inc. announced another price rollback on its products effective Friday morning.

In a media advisory, Petron announced that it will cut gasoline, diesel and kerosene prices by P1 per liter effective 6 a.m. Friday.

"With this adjustment, premium gasolines have been decreased by a total of P2.25/li while diesel, kerosene and regular gasoline have been rolled back by P2.00/li in the past four days. This is to reflect the continuing downward trend in the international oil market," the oil firm said.

Chevron Phil. Inc. will also reduce the prices of its diesel, gasoline and kerosene products by the same amount at 6 a.m. Friday, said communications manager Toby Nebrida.

Unioil Petroleum Philippines Inc. earlier slashed prices of unleaded gasoline by P1 a liter.

It said the rollback, which took effect at 2 p.m. Thursday, was prompted by a decrease in the prices of petroleum products in the international market. With a report from Amy R. Remo