South Korean stocks finished a tad lower Wednesday due to rising uncertainties over the upcoming US. inflation data and worries about the US debt ceiling.

The benchmark Korea Composite Stock Price Index went down 13.55 points, or 0.54 percent, to 2,496.51.

Trading volume was moderate at 623.6 million shares worth 8.76 trillion won ($6.61 billion), with decliners outnumbering gainers 475 to 388.

Foreign investors bought 120.7 billion won worth of local stocks, while institutions dumped 123.2 billion won.

"The KOSPI has taken a breather as investors await the progress on talks about the US. debt limit and the consumer price index data," said Choi Yun-ah from Shinhan Securities Co. "And investor confidence has been weighed down by renewed inflation pressure."

In Seoul, market heavyweights finished mixed.

Tech giant Samsung Electronics fell 1.07 percent to 64,600 won, and its chipmaking rival SK hynix retreated 0.46 percent to 86,900 won.

Leading internet portal operators Naver and Kakao fell 0.47 percent and 1.74 percent to 210,000 won and 56,500 won, respectively.

NCSOFT, a major game developer, lost 1.78 percent to 387,000 won after logging a 32 percent on-year drop in its first-quarter net profit.

But top carmaker Hyundai Motor jumped 2.44 percent to 210,000 won, and its auto parts affiliate Hyundai Mobis climbed 1.12 percent to 226,500 won.

SK Telecom, the country's top wireless carrier, gained 2.37 percent to 49,750 won thanks to its strong quarterly earnings report released earlier in the day.

The local currency ended at 1,324.9 won against the US dollar, down 1 won from the previous session's close. (Yonhap)