South Korean stocks ended lower Wednesday amid lingering woes over the country's ban on short selling. The local currency gained ground against the greenback.

After choppy trading, the benchmark Korea Composite Stock Price Index fell 22.34 points, or 0.91 percent, to close at 2,421.62.

Trading volume was moderate at 461.3 million shares worth 7.54 trillion won ($5.75 billion), with losers outnumbering gainers 498 to 378.

After opening higher, the Kospi climbed as high as nearly 1 percent in line with overnight Wall Street gains but soon lost ground due to a selling spree by foreign and retail investors.

Market watchers cited increased market uncertainty from the short selling ban announced unexpectedly on Sunday.

The Kospi logged its largest-ever daily gain of 134.03 points, or 5.66 percent, on Monday, buoyed by the short selling ban, but it fell 2.33 percent a day later as investors sold shares to profit off steep gains.

"Expectations and disappointments surrounding the ban on short selling have continued to cause ups and downs, and as a result, the domestic stock market will likely continue its volatile trend due to supply concerns, particularly focused on secondary battery-related companies," Han Ji-young, an analyst at Kiwoom Securities, said.

Han advised investors to remain cautious against market volatility for the rest of the week.

Battery stocks took heavy beatings, with industry leader LG Energy Solution sliding 1.24 percent to 437,500 won and smaller rival Samsung SDI tumbling 3.43 percent to 450,000 won.

Tech and chemical shares also lost ground. Chip giant Samsung Electronics shed 1.41 percent to finish at 69,900 won, and LG Chem slumped 2.85 percent to 478,000 won.

Steel and automakers also suffered losses. Top steelmaker Posco Holdings dropped 1.72 percent to 456,500 won, and leading automaker Hyundai Motor and smaller affiliate Kia slipped 0.74 percent and 0.65 percent to 174,800 won and 77,000 won, respectively.

Bio-related stocks, however, fared better, with SK bioscience climbing 1.48 percent to 68,400 won and Celltrion advancing 1.22 percent to 157,500 won.

The local currency ended at 1,310.60 won against the US dollar, down 2.70 won from the previous session's close. (Yonhap)