South Korean shares closed higher Wednesday led by gains in tech shares tracking advances on Wall Street, ahead of the Federal Reserve's rate decision. The local currency gained ground against the US dollar.

The benchmark Korea Composite Stock Price Index added 22.85 points, or 0.84 percent, to close at 2,728.17.

Trade volume was moderate at 499.4 million shares worth 11.5 trillion won ($8.35 billion), with gainers outnumbering losers 502 to 372.

Foreign investors net purchased 234.4 billion won worth of local shares, one day after snapping their three-session buying spree. Institutions also scooped up a net 10.3 billion won while retail investors offloaded 243 billion won.

The Kospi had opened higher, tracking overnight gains of US tech shares, led by Apple Inc.

The Dow Jones Industrial Average slipped 0.31 percent to close at 38,747.42, but the tech-heavy Nasdaq gained 0.88 percent to reach a record high of 17,343.55, with Apple jumping more than 7 percent after the tech giant unveiled its free artificial intelligence.

"Apple was the hero in the US stock market the previous day. Apple's advance led the upward movement of S&P 500 and Nasdaq, but caution will still prevail in the local stock market ahead of the conclusion of the Federal Open Market Committee meeting and the release of the US consumer price index," Hana Securities researcher Kim Dae-wook said.

The outcome of the two-day FOMC is due Wednesday.

In Seoul, large caps closed mixed.

Tech shares closed higher, with industry leader Samsung Electronics soaring 1.73 percent to 76,500 won, while No. 2 chipmaker SK hynix surged 1.18 percent to 215,000 won.

Leading battery maker LG Energy Solution lost 1.40 percent to 351,500 won, with its local rival Samsung SDS slipping 0.51 percent to 154,800 won.

Top cosmetics firm Amorepacific spiked 7.64 percent to 191,700 won, while leading pharmaceutical firm Celltrion tumbled 2.60 percent to 187,600 won.

Autos also closed mixed, with industry leader Hyundai Motor losing 0.37 percent to 270,000 won, while its smaller affiliate Kia added 0.41 percent to 122,500 won.

The local currency closed at 1,376.20 won against the dollar, up 2.20 won from the previous session's close. (Yonhap)