South Korean shares closed lower on Wednesday for a second day, dragged down by sharp declines in semiconductor stocks as higher oil prices and global bond yields took a toll on investor sentiment. Shares of key chipmakers Samsung Electronics (KRX:005930) and SK Hynix (KRX:000660) declined 8% and 10%, respectively, at market close.

The Korea Composite Stock Price Index, or Kospi, decreased by 398.66 points, or 5.8%, to close at 6,471.17. The Kosdaq also fell by 9.74 points, or 1.2%, to close at 824.46.

In economic news, Moody's has revised up its economic growth forecast for South Korea to 3.5%, driven by a boost in semiconductor activity until at least mid-2027.

The rating agency expects GDP growth of 2.7% for the country in 2027.

The forecast for this year is higher than the previous estimates of 2.5% in May and 1.8% in February.

In corporate news, Hyundai Motor's (KRX:005380) 40,000-member labor union plans to carry out a partial strike throughout this week after failing to reach a wage agreement with the automaker's management, Yonhap News reported Tuesday.

The union scheduled four-hour partial strikes on Monday and Tuesday, with plans to continue next week, according to the report.

The union is seeking a 149,600-won increase in monthly base pay and a performance bonus equivalent to 30% of the net profit in 2025. The automaker has offered an 80,000-won monthly base-pay raise, a performance bonus equivalent to 350% of monthly salary plus 10 million won, along with 15 company shares, the report said.

Hyundai Motor did not immediately respond to MT Newswires' request for comment.

Shares of the automaker fell 5% at market close.