South Korea's key stock index opened lower Monday after a four-session losing streak, as investors took to the sidelines on the first day of partially resumed short selling.

The benchmark Korea Composite Stock Price Index (Kospi) fell 5.07 points, or 0.16 percent, to 3,142.79 points in the first 15 minutes of trading.

Beginning Monday, the country's financial authorities lifted short selling ban on 200 market heavyweights on the main bourse and 150 companies on the tech-laden Kosdaq market.

In March last year, the authorities banned the trading practice over a stock market rout triggered by the COVID-19 pandemic.

Market kingpin Samsung Electronics added 0.25 percent, and No. 2 chipmaker SK hynix advanced 0.78 percent.

Internet portal giant Naver moved up 0.97 percent, while chemical maker LG Chem retreated 3.11 percent.

Top pharmaceutical firm Samsung Biologics shed 1.12 percent, and the country's largest automaker Hyundai Motor climbed 1.89 percent.

The local currency was trading at 1,116.95 won to the US dollar, down 4.65 won from the previous session's close. (Yonhap)