South Korean stocks retreated for the second straight session Tuesday as concerns of new coronavirus variants weakened investors' appetite for risky assets. The Korean won rose against the US dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) fell 15.21 points, or 0.46 percent, to close at 3,286.68 points.

Trading volume was moderate at about 1.2 billion shares worth some 14.2 trillion won (US$12.6 billion), with losers outnumbering gainers 549 to 303.

Foreigners sold a net 550 billion won, and institutions offloaded a net 681 billion won, while retail investors bought 1.2 trillion won.

The KOSPI got off to a muted start, taking a cue from new travel bans against the new COVID-19 variants in many parts of the world.

A retreat on steel, financial and tech led the KOSPI's fall amid worries that the spreading Delta variant may derail the global economic reopening.  

"Reports about the increasing Delta variant cases and travel curbs seem to have turned investors risk-averse, pulling down the stock prices in the overall Asian stock markets," Mirae Asset Securities analyst Seo Sang-young said.

In Seoul, market bellwether Samsung Electronics retreated 1.1 percent to 81,000 won, and No. 2 chipmaker SK hynix lost 0.79 percent to 125,000 won.

Internet portal operator Naver added 0.86 percent to 411,500 won, and giant pharmaceutical firm Samsung Biologics advanced 0.36 percent to 846,000 won.

Leading steelmaker POSCO shed 1.98 percent to 347,000 won, and KB Financial Group slumped 1.92 percent to 56,100 won.

Top automaker Hyundai Motor declined 0.62 percent to 239,500 won, but leading chemical firm LG Chem gained 1.08 percent to 839,000 won.

The local currency closed at 1,128.5 won against the US dollar, up 1.8 won from the previous session's close. (Yonhap)