South Korean stocks closed slightly higher on Wednesday, aided by gains in key blue-chips, although foreigners turned to net sellers. The local currency fell slightly against the US dollar.

The benchmark Korea Composite Stock Price Index gained 3.69 points, or 0.17 percent to finish at 2,166.98. Trading volume was moderate at 621.4 million shares worth 5.02 trillion won ($4.5 billion), putting gainers and decliners nearly in a tie 400 to 394.

"Foreign investors are on selling mode after they drove the KOSPI's rally to a 3-month high. It's likely that the market will move in this tight range for some time, until the earnings season," said Hong Seong-bae, an analyst at NH Investment & Securities Co. 

Offshore investors sold off a net 53.4 billion won worth of local shares. They have reduced their holdings in local shares since last week, snapping a two-week buying binge worth a combined 2.62 trillion won between March 6-17. They have scooped up a combined 4.6 billion won this week.

Large-cap tech firms were bullish on anticipation for good quarterly performance. LG Display, a leading flat panel maker, spiked 4.28 percent to 30,450 won following market reports about record-high earnings for the first quarter.

Major chipmaker SK hynix rose 1 percent to 51,300 won after media reported that it is joining the bid to buy the memory chip unit of Japan's Toshiba Corp. Market bellwether Samsung Electronics also finished up 0.72 percent to 2,089,000 won, ahead of the unveiling of its new Galaxy S8 slated this week.

In contrast, mobile carriers and automobiles closed lower, with top mobile carrier SK Telecom sliding 3.07 percent to 252,500 won and No.1 automaker Hyundai Motor losing 2.5 percent to 156,000 won.

The local currency ended at 1,114.20 won against the greenback, down 1.2 won from Tuesday's close.

Bond prices, which move inversely to yields, closed marginally higher. The yield on three-year Treasurys slipped 0.4 basis point to 1.653 percent and the return on the benchmark five-year government bonds shed 0.6 basis point to 1.843 percent. (Yonhap)