South Korean stocks opened steeply lower Monday as the United States and its allies mull ways to suspend imports of Russian crude, raising concerns the soaring oil prices may weigh on corporate performances.

The benchmark Korea Composite Stock Price Index (KOSPI) had retreated 46.26 points, or 1.7 percent, to 2,667.17 points as of 9:17 a.m.

Investor sentiment for risky assets decreased as Brent crude hit an intraday high of US$139 a barrel, the highest since 2008, following reports the US and its allies are working on an embargo against Moscow over the Russian invasion of Ukraine.

Most large caps traded lower due to foreign and institutional sell-offs.

Market bellwether Samsung Electronics lost 1.82 percent, while No. 2 chipmaker SK hynix declined 3.21 percent.

Internet portal operator Naver retreated 2.83 percent, and top carmaker Hyundai Motor decreased 1.45 percent. Leading chemical firm LG Chem moved down 2.8 percent.

The local currency was trading at 1,220.4 won against the US dollar, down 6.2 won from the previous session's close. (Yonhap)