South Korean stocks began sharply lower Wednesday, as signs of a worsening debt crisis in Spain and Greece unnerved investor sentiment, analysts said.

The benchmark Korea Composite Stock Price Index (KOSPI) fell 28.60 points, or 1.59 percent to 1,765.33 in the first 15 minutes of trading.

Shares lost ground across the board, with market bellwether Samsung Electronics slumping more than 2 percent and steelmaker POSCO retreating 1.5 percent.

The yield on Spanish debts rose overnight to the highest level since 2001 and the European Union said chances for Greece to make the bailout requirements were getting slim.

The local currency was trading at 1,153.20 won against the U.S. dollar as of 9:15 a.m., down 7.1 won from Tuesday's close. (Yonhap News)