South Korean stocks turned to losses late Friday morning as concerns about the possibility of US Fed's earlier-than-expected tapering pulled down stock prices.

The benchmark Korea Composite Stock Price Index (Kospi) retreated 20.52 points, or 0.66 percent, to 3,077.31 points as of 11:20 a.m.

Stocks opened with mild gains after the Kospi retreated nearly 2 percent Thursday, marking the biggest daily loss since Feb. 26 and the lowest closing price since early April.

But stocks fell back below the 3,200-point mark in the late morning, largely on market jitters that the Federal Reserve may start tapering its accommodative policies and raise policy interest rates as early as the final quarter of this year.

In Seoul, market kingpin Samsung Electronics traded flat, and No. 2 chipmaker SK hynix advanced 0.49 percent.

Internet portal operator Naver slipped 0.12 percent, while pharmaceutical giant Samsung Biologics gained 1.74 percent.

Top automaker Hyundai Motor declined 1.69 percent, but leading chemical firm LG Chem climbed 0.45 percent.

The local currency was trading at 1,176.9 won to the US dollar, down 0.7 won from the previous session's close. (Yonhap)