MANILA, Philippines -- (UPDATE 3) Oil firms Pilipinas Shell, Petron Corp. and Phoenix Petroleum will increase gasoline prices and roll back diesel and kerosene prices effective Tuesday, company officials said.

At 12:01 a.m., Shell will increase gasoline prices by 50 centavos per liter and roll back diesel and kerosene prices by the same amount, said company vice president for communications Roberto Kanapi.

The adjustments were made "to reflect movements in international product prices," he said.

Petron and Phoenix will implement the same price adjustments at 6 a.m. Tuesday, said Petron spokesperson Virginia Ruivivar and Phoenix assistant vice president for corporate affairs Raymond Zorrilla.

While it will raise gasoline prices by 50 centavos per liter at 6 a.m., Chevron will keep its diesel and kerosene prices steady, its communications manager Toby Nebrida said.