BEIJING, April 12 (Xinhua) -- China will raise the retail prices of gasoline and diesel from Friday, the fourth increase this year, the country's top economic planner announced Thursday.

As international oil prices increase, the retail prices of gasoline and diesel will rise by 55 yuan (about 8.75 U.S. dollars) and 50 yuan per tonne, respectively, according to the National Development and Reform Commission (NDRC).

Under the current pricing system, if global crude price changes lead to price increases or declines of more than 50 yuan per tonne for domestic refined oil products, and remain so for 10 working days, gasoline and diesel prices are adjusted accordingly.

Global oil prices rose this week as both Brent and WTI crude prices reached the highest since December 2014.

The NDRC said it would closely monitor the effects of the current pricing mechanism and make changes in response to global fluctuations.

It has asked major Chinese oil companies, including China National Petroleum, China Petrochemical and China National Offshore Oil, to ensure stable supply and pricing.