South Korean shares closed 1.5 percent lower on Thursday, hit by heavy foreign selling focused on technology shares and as investors sold off large caps linked to the expiry of derivatives and given an uncertain market outlook.
The central bank's decision to hold its overnight call rate target at a record low of 3.75 percent had little impact on the stock market as the move had been widely anticipated, participants said.
The benchmark Korea Composite Stock Price Index (KOSPI) finished down 1.54 percent at 782.30 points.
Foreign investors sold a net 551.9 billion won ($477.8 million) worth of shares, the highest since April 30 when China said it would take steps to slow its economic growth.
Lingering worries over a possible early rise in US interest rates and a delayed recovery in domestic demand also weighed on investment sentiment, dealers said.
South Korean consumers grew more pessimistic about future economic conditions in May, after a turn for the better in April, government data showed on Thursday.
Shares in Samsung Electronics Co Ltd, the world's top memory chip maker, dropped 3.11 percent to close at 468,000 won, hit by heavy foreign selling following a 3.24 percent drop in US chip shares.
South Korea's top home appliance maker, LG Electronics Inc, shed 4.03 percent to 57,100 won while display maker Samsung SDI Co lost 2.33 percent to end at 126,000 won.
Investors also offloaded shares in Kirin and Samlip Foods after the government included them among a list of firms that were also found to have used rotten ingredients. Kirin plunged by a daily permissible 15 percent limit to 770 won and Samlip Foods dropped by 10.78 percent to end at 3,105 won.
Trade volume totalled 436.5 million shares valued at 2.79 trillion won. Decliners led gainers by 442 to 278 with 75 stocks unchanged.
The June KOSPI 200 futures index ended down 0.10 points at 101.85 and the underlying KOSPI 200 spot index fell 2.01 points to 100.58. The junior Kosdaq ended down 0.13 percent at 400.09 points.