SEOUL, Sept. 15 (Xinhua) -- South Korea's trade surplus fell sharply to 500 million U.S. dollars in August as imports grew faster than exports, the customs office said Thursday.

The nation's trade surplus stood at 500 million U.S. dollars in August, sharply down from 4.9 billion U.S. dollars tallied in the previous month, the Korea Customs Service (KCS) said in an statement by e-mail.

For the first eight months of this year, the accumulative trade surplus amounted to 21 billion U.S. dollars, down from 23.7 U.S. billion dollars the same period of last year.

The nation's trade balance have been in the black for 19 straight months in August, but the surplus were sharply down compared with a month earlier due to weaker exports that were attributed partly to fewer working days caused by summer vacations, according the KCS.

Exports grew 25.9 percent to reach 45.9 billion U.S. dollars last month helped by solid demand for oil products, cars and ships that jumped by 82.7 percent, 33.7 percent and 79.9 percent on an on-year basis respectively.

By country, overseas shipments to Japan increased by 44.9 percent on an on-year basis in August, with exports bound for China and the Southeast Asian countries growing 21.2 percent and 39.2 percent each. Exports to European Union and the United States also rose 12 percent and 6.9 percent respectively last month.

Imports expanded 28.9 percent on an on-year basis to 45.5 billion dollars in August due to continued increase in raw material costs, according to the office. The year-on-year import growth of iron ore, crude oil and natural gas reached 62.1 percent, 45.8 percent and 32.9 percent respectively.