Seoul shares closed down for a third straight session Friday as investors await the result of an impeachment vote against President Yoon Suk Yeol on Saturday over his botched martial law attempt. The Korean won fell against the US dollar.

The benchmark Korea Composite Stock Price Index fell 13.69 points, or 0.56 percent, to close at 2,428.16. This week, the index lost 1.1 percent.

Trade volume was moderate at 620.82 million shares worth 10.48 trillion won ($7.4 billion), with losers outpacing winners 657 to 248.

Foreigners and individuals sold a combined 887.07 billion won worth of stocks, exceeding institutions' stock purchases valued at 826.08 billion won.

The tech-heavy Kosdaq index closed 1.43 percent lower at 661.33.

The political turmoil that hit the stock market began Tuesday night when Yoon abruptly declared martial law, accusing the main opposition party of paralyzing the government with impeachment motions and a downsized budget bill.

But he abandoned it just hours later following a National Assembly resolution to rescind it.

Opposition parties submitted an impeachment motion, saying Yoon gravely violated the Constitution and the law. The impeachment vote is set for Saturday.

On Friday, ruling People Power Party leader Han Dong-hoon called for a swift suspension of Yoon's presidential power, saying he ordered the arrests of prominent politicians under the martial law.

Large-cap stocks were mixed across the board.

No. 2 chipmaker SK hynix fell 3.41 percent to 167,100 won, top carmaker Hyundai Motor declined 0.49 percent to 203,500 won, and state-run utility firm Korea Electric Power Corp. shed 1.85 percent 21,250 won.

National flag carrier Korean Air dropped 1.02 percent to 24,300 won, steelmaker POSCO Holdings declined 0.38 percent to 265,500 won, and shipping firm HMM was down 1.15 percent to 18,000 won.

Among gainers, market bellwether Samsung Electronics rose 0.74 percent to 54,100 won, leading refiner SK Innovation climbed 2.61 percent to 114,200 won, and leading battery maker LG Energy Solution was up 2.23 percent to 390,500 won.

The local currency was trading at 1,419.20 won against the greenback at 3:30 p.m., down 4.1 won from the previous session.

Bond prices, which move inversely to yields, closed lower. The yield on three-year Treasurys rose 1.7 basis points to 2.620 percent and the return on the benchmark five-year government bonds climbed 1.3 basis points to 2.633 percent. (Yonhap)