BEIJING - China's crude oil output fell 9.9 percent year on year in August, the biggest monthly drop since 2003 as refineries slashed production amid sluggish global oil prices, data from the National Bureau of Statistics showed Monday.

Imports, on the other hand, have trended upward after private refineries were given permission to import crude last year.

In the first eight months, China's crude oil imports rose 13.5 percent compared with the same period last year, while refined oil output gained 2.1 percent.

China's oil giants plan to reduce oil output due to flagging prices. Sinopec, the largest oil refiner in China, and PetroChina, the largest oil and gas producer, have both lowered their oil production targets for 2016.

On Sunday, the National Development and Reform Commission (NDRC) decided to lower retail prices of gasoline and diesel, tracking subdued global crude oil prices due to market worries about an agreement on freezing production, rising yields in countries including Iran and weak US demand.

"The prices will likely remain low in the short term, fluctuating between $40 to $50 per barrel," said NDRC researcher Zhao Gongzheng.