Korean stocks closed slightly lower Monday as investors took to the sidelines ahead of the Fed chair's speech that could provide clues to the U.S. central bank's monetary policy, analysts said. The local currency gained ground against the U.S. dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) shed 1.27 points, or 0.06 percent, to close at 1,982.54. Trade volume was moderate at 405.98 million shares, with losers beating winners 479 to 330.

The market opened higher, but the gains were trimmed by foreign selling. Coupled with expanding sell-off by institutions and retail investors, the index turned south later in the day.

"Despite low chances of an immediate rate hike, investors seem to want to be assured by Fed Chair Yellen through her speech planned for this week," said Bae Sung-jin, an analyst at Hyundai Securities.

Fed Chair Janet Yellen is to deliver a speech at an economic club meeting on Tuesday local time amid concerns recently heightened by some hawkish comments by some high-ranking Fed officials.

Investors are paying close attention to her as they are trying to get any clues as to whether and when the U.S. central bank would raise its interest rate.

"The market could rebound after that if investors are sure that an immediate rate hike is off the table," he added.

Chipmaking giant SK hynix ended down 2.06 percent to 28,550 won, while chemical maker LG Chem shed 1.08 percent to 319,500 won. Cosmetic producer AmorePacific fell 1.4 percent to 387,000 won.

Auto parts maker Hyundai Mobis was off 0.4 percent to 248,500 won following a brokerage report that forecast weak first quarter earnings.

Tech and telecom issues, meanwhile, ended bullish. Samsung Electronics gained 0.47 percent to 1,294,000 won with top mobile carrier SK Telecom rising 1.45 percent to 210,500 won. 

The local currency closed at 1,166.2 won against the U.S. greenback, up 3 won from Friday's close. (Yonhap)