Seoul shares started over 1.8 percent lower Thursday after the US Federal Reserve cut its rate for the third consecutive time but signaled fewer rate cuts next year. The Korean won opened sharply lower against the US dollar.

The benchmark Korea Composite Stock Price Index shed 45.47 points, or 1.83 percent, to 2,438.96 in the first 15 minutes of trading.

The Korean won also plummeted to breach 1,450 won per US dollar, reaching a 15-year low. It was trading at 1,450.8 won against the greenback at 9:15 a.m., down 15.3 won from the previous session.

Overnight, the US central bank cut its key lending rate by a quarter percentage point to the 4.25 to 4.50 percent range but signaled a slower monetary easing pace in 2025 with hotter-than-expected inflation readings.

The Fed's hawkish rate cut drove down major US indexes. The Dow Jones Industrial Average fell 2.58 percent, the S&P 500 dropped 2.95 percent, and the tech-heavy Nasdaq Composite slid 3.56 percent.

In Seoul, most big-cap shares kicked off in negative territory.

Tech behemoth Samsung Electronics lost 2 percent, while its chipmaking rival SK hynix shot down 4.03 percent.

Top automaker Hyundai Motor dropped 1.62 percent, and its sister Kia fell 2.55 percent.

Steel giant Posco Holdings shed 2.79 percent, and leading chemical producer LG Chem slid 3.08 percent.

Major refiner SK Innovation also plummeted 3.11 percent. (Yonhap)