South Korean stocks opened weaker Wednesday ahead of a key rate decision by the US Federal Reserve this week.

The benchmark Korea Composite Stock Price Index slid 6.01 points, or 0.24 percent, to 2,492.80 in the first 15 minutes of trading.

Overnight, US stocks closed mixed as Wall Street waited for the Fed's latest decision on interest rates. The Dow Jones Industrial Average inched up 0.35 percent, while the S&P 500 shed 0.06 percent. The Nasdaq composite dropped 0.76 percent.

In Seoul, tech shares took beatings, with Samsung Electronics, which reported a 34.4 percent on-year decrease in fourth quarter operating profit, dropping 0.94 percent. Chip rival SK hynix also plummeted 2.19 percent.

Internet portal operators Naver and Kakao also traded lower, dropping 1.67 percent and 1.29 percent, respectively.

Auto and energy-related shares, however, gained ground, with Hyundai Motor rising 0.84 percent and leading chemical manufacturer LG Chem jumping 2.46 percent.

The local currency was trading at 1,330.25 won against the US dollar, down 0.85 won from the previous session's close. (Yonhap)