South Korea's exports fell in the June 1-20 period on fewer business days compared to the same period of last year, customs office data showed Thursday.

Exports, which account for about half of the export-driven economy, amounted to 30.3 billion U.S. dollars in the June 1-20 period, down 4.8 percent from the same period of last year, according to the Korea Customs Service.

It was mainly attributable to fewer business days. The number of working days in the cited period declined to 13.5 days this year from 14.5 days in the same period of last year.

The daily average exports, which exclude the working day effect, rose 2.2 percent to 2.24 billion dollars.

Exports for semiconductors, oil products and automobiles posted a double-digit increase in the period, but those for telecommunication devices, such as smartphones, slumped as domestic manufacturers increased production in overseas factories. Ship exports tumbled 89.1 percent on lower shipbuilding orders.

Exports to China, South Korea's biggest trading partner, advanced 28.5 percent, with those to the United States and the European Union growing by a double digit.

Shipments to Japan gained 12.3 percent, but those to Vietnam and Australia declined by a double digit.

Trade surplus stood merely at 26 million dollars in the cited period as imports expanded 13 percent.