Manila, Jan. 23 -- Oil prices are projected to rise by as much as PHP1.40 per liter next week amid supply concerns.

In a Friday advisory, Jetti Petroleum President Leo Bellas said diesel prices could rise by PHP1.20 to PHP1.40 per liter, while gasoline prices may increase by PHP0.30 to PHP0.50 per liter, based on Asian benchmark prices and foreign exchange movements as of Thursday.

The projected hike in gasoline prices would be the third week in-a-row and fifth for diesel.

"Worries of tightening near-term supply due to the temporary halting of production at two large oilfields in Kazakhstan and export constraints in the Black Sea are supporting the upward pressure on oil prices this week," Bellas said.

Another factor is the demand opt...