SEOUL, April 16 (Xinhua) -- South Korea's trade balance stayed in the black for 74 months through March thanks to brisk exports coming from strong demand for locally-made semiconductors, customs data showed Monday.

Final figure for trade surplus was 6.8 billion U.S. dollars in March, staying in the black since February 2012, according to the Korea Customs Service.

The longtime surplus was attributable to faster growth in exports than imports. Outbound shipments, which account for about half of the export-driven economy, gained 6.1 percent over the year to 51.6 billion dollars in March, while imports rose 5.2 percent to 44.8 billion dollars.

Chip exports surged 43.9 percent in March from a year earlier, leading last month's export expansion. Oil product shipments added 1.1 percent, but those for automobile and ships declined 8.1 percent and 30.9 percent each.

Export of telecommunication devices, such as smartphone, fell 9.2 percent as local companies increased production in overseas factories.

Shipments to China, South Korea's biggest trading partner, advanced 16.6 percent, but those to the United States, the No. 2 trading partner of South Korea, fell 1 percent.

Crude oil imports rose 2.5 percent, leading the overall import increase in raw materials. Imports for consumer and capital goods climbed 7.4 percent and 4.2 percent in March, respectively.