Seoul: Seoul stocks opened sharply lower on Monday amid renewed energy price concerns after Tehran warned it could indefinitely close the Hormuz Strait, a key oil route. The benchmark Korea Composite Stock Price Index (KOSPI) fell 273.11 points, or 4.72 percent, to 5,508.09 in the first 15 minutes of trading.

According to Yonhap News Agency, the Korea Exchange, South Korea's main bourse operator, issued a sell-side sidecar soon after the opening bell amid a sharp drop, temporarily halting program trading. On Friday, major stock indexes on Wall Street closed lower as the war in Iran continued to ripple through financial markets. The S and P 500 fell 1.5 percent, and the tech-heavy Nasdaq gave up 2 percent.

Investor sentiment was dampened as the war in Iran has been sending energy prices to record levels, raising concerns about inflation and complicating the outlook for U.S. Federal Reserve's policy direction. Fed Gov. Christopher Waller signaled that he may take a more conservative approach to interest rates in an interview with CNBC on Friday.

Adding further concerns is the recent warning from Iran that it would shutter the Hormuz Strait, in response to U.S. President Donald Trump's threat to "obliterate" Iran's power plants if the crucial waterway was not reopened in 48 hours.

In Seoul, most large-cap stocks were trading sharply lower. Market top-cap Samsung Electronics fell 5 percent, while its chipmaking rival SK hynix retreated 5.56 percent. Top automaker Hyundai Motor fell 4.09 percent, defense giant Hanwha Aerospace shed 3.86 percent, and major financial group KB Financial moved down 4.06 percent.

The Korean won was trading at 1,503.7 won against the U.S. dollar as of 9:15 a.m., down 3.1 won from the previous session.