South Korean shares closed slightly lower Wednesday as foreigners turned to selling amid concerns of a US rate hike and a further decline in global oil prices. The local currency lost ground against the US greenback.

The benchmark Korea Composite Stock Price Index slipped 6.17 points, or 0.3 percent, to 2,043.76. Trading volume was slim at 280.2 million shares worth 4.03 trillion won ($3.59 billion).

Gainers outnumbered losers 404 to 388.

The index opened slightly higher but later pared earlier gains as investors sought to lock in the early gains.

Institutions dumped a net 26.4 billion won worth of local stocks, remaining net sellers for seven consecutive sessions since last Tuesday.

Foreign investors sold a net 76.3 billion won, while retail investors offloaded 17.7 billion won, ending their three-day buying streak.

"Institutions tend to offload their holdings when the KOSPI reaches over 2,000 points. However, their seven-day selling spree may indicate that their selling will likely shrink in the upcoming days," Kiwoom Securities analyst Seo Sang-young said.

"There were two major reasons why foreign investors turned to selling today. One is growing concerns over a US rate hike, and the other is concerns over a drop in oil prices sparked by a US report that its crude stockpile jumped by nearly 4.5 million barrels last week," he added.

Large caps closed mixed, while market bellwether Samsung Electronics suffered a large setback amid apparent profit-taking behaviors by investors.

Samsung shares plunged 2.02 percent to 1,653,000 won, one day after they climbed to a new record high of 1,687,000 won.

Local industry leader Hyundai Motor spiked 2.26 percent to 135,500 won, with its smaller affiliate Kia Motors adding 1.31 percent to 42,550 won.

Their auto parts making affiliate Hyundai Mobis, on the other hand, lost 0.79 percent to 250,000 won.

Steelmaking giant POSCO surged 3.23 percent to 224,000 won, but top cosmetics maker AmorePacific lost 0.77 percent to 384,500 won.

The local currency closed at 1,122.00 won against the US dollar, down 6.40 won from the previous session's close. (Yonhap)