South Korean stocks tumbled at the opening bell Wednesday, driven by big IT and bio shares, after the hotter-than-expected US inflation data sparked fears the Federal Reserve would push ahead with aggressive monetary tightening.

The Kospi sank 62.19 points, or 2.54 percent, to 2,387.35 in the first 15 minutes of trading.

The US August consumer price index slowed to an 8.3 percent on-year gain, which was above the consensus of an 8.1 percent increase.

The core CPI, which excludes food and energy prices, rose 6.3 percent from a year earlier, topping forecasts of a 6.1 percent on-year gain.

The strong inflation data fueled expectations that the Fed will go ahead with another sharp interest rate hike by three-quarters of a percentage point in the monetary policy meeting next week.

The data sent Wall Street to post the biggest fall in two years.

In Seoul, most shares took a beating, with internet portal provider Naver plummeting more than 5 percent and biotech firm Samsung Biologics dipping over 3 percent.

Tech heavyweight Samsung Electronics also tumbled around 3 percent.

The local currency started sharply lower against the US dollar, breaching the 1,390 won mark for the first time in more than 13 years. The Korean won was trading at 1,394.50 won against the greenback as of 9:15 a.m., down 20.9 won from Tuesday's close. (Yonhap)