South Korean stocks closed slightly lower Thursday as investors took to the sidelines ahead of top Fed officials' remarks that could provide a glimpse of the U.S. central bank's monetary policy direction, analysts said. The local currency lost ground against the U.S. dollar.

The benchmark Korea Composite Stock Price Index fell 3.91 points to 1,993.36. Trading volume was light at 382.5 million shares worth 3.4 trillion won ($2.9 billion), with winners surpassing losers 454 to 344.

"Concerns over a rate hike in the U.S. kept weighing on investor sentiment. In particular, the speech that major Fed officials are going to deliver also seems to be serving as a drag," said Koh Seung-hee, an analyst at KDB Daewoo Securities Co.

"Downward pressure like this will likely be here to stay until the FOMC meeting in December is over, possibly clearing up the uncertainty," he added.

Federal Reserve Chair Janet Yellen, Vice Chair Stanley Fischer and other top officials are to speak at a conference later Thursday local time.

Domestically, the decision by the Bank of Korea earlier in the day to keep its key interest rate unchanged did not affect the market much as it was in line with the consensus, Koh said.

Foreigners remained a net seller, by unloading a net 212 billion won worth of shares. Institutions joined by selling 30 billion won worth of shares.

Tech bellwether Samsung Electronics ended down 1.2 percent to 1,317,000 won, and No. 1 automaker Hyundai Motor fell 1.53 percent to 160,500 won. Steel giant POSCO shed 2.28 percent to 171,500 won.

State-run power monopoly Korea Electric Power Corp. also lost 2.17 percent to close at 49,600 won.

Insurers along with other financial issues bounced back from the previous day's declines. Samsung Life Insurance jumped 3.69 percent to 112,500 won.

The local currency ended at 1,158.2 won against the greenback, down 3.3 won from Wednesday's close. (Yonhap)