South Korean stocks opened lower Wednesday, tracking Wall Street losses overnight as investors awaited the US Federal Reserve chairman's congressional testimony.

The benchmark Korea Composite Stock Price Index slid 6.04 points, or 0.23 percent, to 2,598.87 in the first 15 minutes of trading.

Overnight, all three major US equity indexes ended in negative territory, as a recent market rally paused ahead of Fed Chair Jerome Powell's congressional testimony slated for Wednesday and Thursday.

The Dow Jones Industrial Average fell 0.72 percent, the S&P 500 went down 0.47 percent and the Nasdaq Composite declined 0.16 percent.

Market watchers are closely looking for any clues as to when and if the US central bank will resume its monetary tightening campaign. The Fed has warned more rate hikes could come by the year-end to tame high inflation.

In Seoul, mega-cap shares opened mixed.

Market behemoth Samsung Electronics slid 0.42 percent, while SK hynix added 0.52 percent.

Top battery maker LG Energy Solution gained 0.36 percent and Samsung SDI increased 1.42 percent.

Auto stocks lost ground, with Hyundai Motor retreating 0.51 percent and Kia falling 0.49 percent.

The local currency was trading at 1,288.8 won against the US dollar at 9:15 a.m., down 8.5 won from the previous session's close. (Yonhap)