South Korean stocks retreated for a third consecutive session Tuesday as investors took to the sidelines ahead of a meeting of the US Federal Open Market Committee (FOMC). The Korean won fell against the US dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) lost 31.71 points, or 0.46 percent, to close at 2,987.95 points.

Trading volume was moderate at about 566 million shares worth some 9.2 trillion won (US$7.8 billion), with losers outnumbering gainers 574 to 284.

Foreigners sold a net 359 billion won and institutions offloaded 198 billion won. Retail investors bought 512 billion won.

The KOSPI dropped below the 3,000-point level as investors weighed the possibility of the Fed quickening its stimulus withdrawal and making hawkish signals about its key interest rate.

Overnight, the tech-heavy Nasdaq composite lost 1.39 percent and the Dow Jones Industrial Average decreased 0.89 percent.

"Most sectors, except for some pharmaceuticals, retreated over investors' wariness against the FOMC (meeting results)," Kiwoom Securities analyst Kim Sae-hun said.

"It is likely that the investors would take their wait-and-see mode until the FOMC uncertainties are resolved," he added.

Most large caps closed lower in Seoul.

Top cap Samsung Electronics added 0.26 percent to 77,000 won, while No. 2 chipmaker SK hynix declined 0.41 percent to 121,000 won.

Electric car battery maker LG Chem slumped 5.01 percent to 701,000 won, Samsung SDI lost 3.27 percent to 680,000 won, and financial payment service Kakao Pay dipped 6.05 percent to 178,500 won.

Among gainers, pharmaceutical giant Samsung Biologics climbed 2.06 percent, with Celltrion moving up 0.49 percent to 206,000 won.

The local currency closed at 1,182.6 won against the US dollar, down 1.8 won from the previous session's close. (Yonhap)