SEOUL: The South Korean won posted its biggest daily gain against the dollar in three weeks on Wednesday as the greenback broadly fell on hopes of progress in Greek debt talks and after a jump in European bond yields.

Meanwhile, investors were wary of intervention by foreign exchange authorities to trim the local currency's appreciation to the yen. The won closed local trade down 0.7 percent at 1,104.7 to the dollar, posting its best daily percentage gain since May 14.

It snapped a six-day losing streak.

The Korea Composite Stock Price Index (KOSPI) erased early gains to fall 0.7 percent to 2,063.16 points, the lowest close since April 9.

It closed at 2,078.64 on Tuesday.

Copyright Reuters, 2015