Oil firms operating in the Philippines lowered pump prices for the third straight week as weak demand for refined petroleum products persist in the international market.

Petron, Shell, and Seaoil said in separate announcements Monday that they were set to roll back prices by P0.10 per liter for diesel and by P0.35/L for kerosene starting 12:01 a.m. January 21.

PTT Philippines is also cutting diesel prices by P0.10 per liter this week. The adjustments make up the second round of rollbacks for the year. As such, major fuel products gasoline and diesel have so far decreased by P1.45/L for diesel and P0.85/L for gasoline.

"Fuel prices in the international market remain weak on concerns of excessive supply but peso depreciation against the dollar following the release of strong economic data from the U.S., particularly its retail industry, partially offset the effect of falling fuel prices,” PTT said.

While other oil firms have not announced their price changes, they tend to track each other’s adjustments as most of the fuel products in the country come from imports.

The year 2014 has so far only had oil price rollbacks. The first set of price cuts was implemented on Jan 7 with kerosene prices trimmed by P0.25 per liter and diesel prices by P0.45 per liter.

Another round of price drops was implemented on Jan. 13, with diesel prices cut by P0.90 per liter, gasoline by P0.85/L, and kerosene by P1.10/L. Analysts see continuing to see price pressure on fuel as U.S. crude supplies grow amid prospects that Iranian oil exports may stabilize.