MANILA, Philippines ? (UPDATE) Chevron Philippines and Pilipinas Shell will roll back prices of diesel, kerosene and gasoline by P1 effective 12:01 a.m. Thursday, according to their officials.

But Roberto Kanapi, Shell vice president for communications, said the cutback would not apply to their e10 product, the price of which would be reduced by P0.75 a liter.

Toby Nebrida, communications manager of Chevron Phils., and Kanapi made the announcements Wednesday after Malacañang asked oil companies earlier in the day to reduce prices amid the continuing decline of the cost of crude in the world market.

On Tuesday, Senator Juan Ponce Enrile threatened to impose a tax on excess profits of oil firms if they would not cut back their prices.

Kanapi said the reductions were a ?product of our weekly assessment and world oil prices.?