South Korean shares ended sharply lower Tuesday as concerns emerged over the U.S. economy following downbeat manufacturing data. The benchmark Korea Composite Stock Price Index (KOSPI) plunged 33.11 points, or 1.72 percent, to close at 1,886.85. It was the first time in around five months that the main index fell below the 1,900 level. Trading volume stood at 246.73 million shares worth 4.43 trillion won (4.1 billion U.S. dollars). Negative economic data in the United States worsened market sentiment. Manufacturing activities of the world's largest economy weakened to the lowest in eight months in January. The negative data came amid lingering worries about the U.S. Federal Reserve's additional stimulus cut. The U.S. central bank decided to scale back its monthly bond purchases by 10 billion dollars further to 65 billion dollars starting from this month after reducing the same size in the prior month. Fears spread that the Fed may continue to cut back on its asset purchases despite the negative economic data. Foreigners dumped a net 663.6 billion won worth of local stocks, offsetting purchases by retail and institutional investors worth 366 billion won and 264.8 billion won each. Most large-cap shares ended bearish. Market bellwether Samsung Electronics declined 1.8 percent, and memory chip giant SK Hynix tumbled 3.8 percent. Top wireless carrier SK Telecom retreated 3.3 percent, but the nation's No. 2 carmaker Kia Motors rose 0.8 percent. The South Korean currency finished at 1,083.8 won against the greenback, up 0.7 won from Monday's close. Bond prices ended higher. The yield on the liquid three-year treasury notes declined 0.03 percentage point to 2.85 percent, and the return on the benchmark 10-year government bonds tumbled 0.07 percentage point to 3.54 percent.