South Korean exports were worse than expected in December, bearing the brunt of slowdowns in China and other key trading partners, as well as an extended slump in oil prices, government data showed Friday.

   The country's outbound shipments sank 13.8 percent last month from a year earlier to $42.64 billion, smaller than the market estimate of $44.75 billion. The December figure also marks an on-year drop for the 12th straight month.

   Its imports also sank 19.2 percent on-year to $35.47 billion last month, according to the data compiled by the Ministry of Trade, Industry and Energy.

   Asia's fourth-largest economy logged a trade surplus of $7.16 billion last month.

   "A drop in oil prices was the main reason behind slumping exports," the ministry said. A decline in exports of oil-related products accounted for 64 percent of the overall drop in exports, according to the ministry.

   For the whole of 2015, the country's exports plunged 7.9 percent on-year to reach $527 billion, while its imports dropped 16.9 percent on-year to $437 billion.

   Its annual trade surplus reached a record high of $90.4 billion, the data showed.

   Exports of oil and petrochemical products dropped 37 percent and 21 percent, respectively, last year, while outbound shipments of cosmetics and OLED surged 54 percent and 25 percent.

   The price of Dubai crude, South Korea's benchmark, stood at $50.7 per barrel in 2015, a sharp drop from the previous year's average of $96.6 per barrel.

   "Oil prices would be the biggest swing factor for a recovery in exports," said Na Sung-hwa, director general of the ministry's export-import division. "We need to monitor other factors, such as an additional rate hike in the U.S."

   Vietnam emerged as South Korea's third-largest export destination with shipments to the Southeast Asian country increasing 24 percent.

   But exports to the United States, China and the European Union dropped 0.6 percent, 5.6 percent and 6.9 percent, respectively, the data showed.

   The ministry expects this year's exports to grow 2.1 percent on-year with imports also rising 2.6 percent.

   "A mild recovery in the global economy and trade are expected this year, but downside risks, such as a deepening slowdown in emerging markets and a further drop in oil prices, also exist," the ministry said. (Yonhap)