The Korean won edged down in the local platform while bond yields rose.
At 06:32 GMT, the KOSPI was down 27.10 points, or 1.13 percent, at 2,375.06. The benchmark index closed at its weakest level since Feb. 9.
The won was quoted at 1,082 per dollar on the onshore settlement platform, 0.16 percent weaker than its previous close at 1,080.3.
In offshore trading, the won was quoted at 1,081.33 per US dollar, down 0.21 percent from the previous day, while in one-year non-deliverable forwards it was being transacted at 1,071.15 per dollar.
MSCI's broadest index of Asia-Pacific shares outside Japan was down 0.88 percent, after US stocks ended the previous session with mild gains. Japanese stocks weakened 0.66 percent.
The KOSPI is down around 2.6 percent so far this year, and down by 4.74 percent in the previous 30 days.
The current price-to-earnings ratio is 12.10, the dividend yield is 1.28 percent and the market capitalisation is 1,242.04 trillion won.
The trading volume during the session on the KOSPI index was 304,709,000 shares, and of the total traded issues of 887, the number of advancing shares was 210.
Foreigners were net sellers of 98,428 million won worth of shares.
The U.S dollar has risen 1.37 percent against the won this year. The won's high for the year is 1,056.67 per dollar on Jan. 14 and low is 1,098.4 on Feb. 6.
In money and debt markets, March futures on three-year treasury bonds rose 0.05 points to 107.65.
The Korean 3-month Certificate of Deposit benchmark rate was quoted at 1.65 percent, while the benchmark 3-year Korean treasury bond yielded 2.315 percent, higher than the previous day's 2.28 percent.