South Korean stocks opened a tad higher Wednesday, led by an advance by pharmaceutical and financial heavyweights.

The benchmark Korea Composite Stock Price Index rose 4.85 points, or 0.20 percent, to 2,423.52 in the first 15 minutes of trading.

Pharmaceutical giants led the gain, with leading pharmaceutical firm Samsung Biologics jumping 3.73 percent on expectations of rising overseas orders. SK Biopharmaceuticals gained 1.83 percent.

Among financial large caps, Hana Financial Group added 1.92 percent, and Woori Financial Group jumped 1.99 percent.

Other large caps mostly fell.

Market behemoth Samsung Electronics slipped 0.17 percent, with No. 2 chipmaker SK hynix retreating 0.74 percent.

Internet giant Naver lost 0.48 percent, with its rival Kakao remaining flat.

Top automaker Hyundai Motor dropped 1.68 percent, and leading chemical firm LG Chem fell 0.66 percent.

The local currency was trading at 1,1,185.85 won against the US dollar, down 0.25 won from the previous session's close. (Yonhap)