An electronic board showing the Korea Composite Stock Price Index at a dealing room of the Hana Bank headquarters in Seoul on Friday. (Yonhap)

South Korean stocks ended slightly lower Friday, snapping three consecutive sessions of gains, as investors sat on the sidelines ahead of Federal Reserve Chair Jerome Powell speech later in the day. The local currency fell against the US dollar.

The benchmark Korea Composite Stock Price Indexfell 5.98 points, or 0.22 percent, to close at 2,701.69.

Trade volume was moderate at 324 million shares worth 8.1 trillion won ($6.05 billion), with gainers outnumbering losers 429 to 428.

Foreigners sold a net 241.9 billion won worth of shares, while individuals offloaded a net 103.2 billion won. Institutions bought a net 334.6 billion won.

Investors took a wait-and-see approach as Powell is set to deliver a speech at the Jackson Hole meeting after market hours, which will give clues on the Fed's monetary policy direction.

Analysts noted that investors are also keeping a watchful eye on Nvidia's earnings report due next week, which could provide further insight into the sustainability of the momentum in tech shares.

"The speech by Powell, which will be held at 11:00 p.m. Korean time, is likely to determine the market's sensitivity to economic indicators that will be released next week," said Lee Kyoung-min, a researcher at Daishin Securities.

Top tech giant Samsung Electronics shed 0.77 percent to 77,700 won, and No. 2 chipmaker SK hynix lost 2.93 percent to 185,500 won.

Chemical shares finished bearish as well, with LG Chem falling 0.32 percent to 315,000 won and oil refiner SK Innovation decreasing 0.75 percent to 105,400 won. Cosmetics giant AmorePacific moved down 0.08 percent to 121,800 won.

Leading carmaker Hyundai Motors moved up 1.81 percent to 252,500 won, and its sister Kia added 1.56 percent to 104,000 won. Auto parts giant Hyundai Mobis climbed 0.23 percent to 219,500 won.

The local currency was trading at 1,338.8 won against the dollar as of 3:30 p.m., down 4.1 won from the previous session. (Yonhap)