NEW YORK: The New York Stock Exchange suspended trading in all stocks Wednesday morning after suffering technical problems.
"The issue we are experiencing is an internal technical issue and is not the result of a cyber breach," NYSE said on Twitter.
"We chose to suspend trading on NYSE to avoid problems rising from our technical issue."
The exchange, the leading US platform for trading equities, halted trade just after 1530 GMT (11:30 EST), freezing the buying and selling of the shares of many of the world's largest companies.
But stocks listed on the NYSE, which is owned by Intercontinental Exchange (ICE), continued to trade on the Nasdaq and BATS, the third largest US exchange.
"Nasdaq systems are operating normally and are trading all symbols including Tape A (NYSE) securities," Nasdaq said via Twitter.
It was the second major US exchange outage sin nearly two years. The Nasdaq froze trade for three hours in August 2013 due to technical problems.
The outage also came on the same day as United Airlines grounded planes at US airports for an hour due to a computer glitch.
The Department of Homeland Security said it was investigating but so far had found no sign of malicious activity in either of the incidents.
There is no indication "at this time" that the halt in trading at the New York Stock Exchange was the result of any foul play, the US Department of Homeland Security said Wednesday.
There are "no signs of malicious activity at this time," a department spokesperson told AFP, adding: "We're still investigating."
At 1636 GMT, the Dow Jones Industrial Average was at 17,567.28, down 209.63 points (1.18 percent).
The broad-based S&P 500 fell 27.48 (1.32 per cent) to 2,053.86, while the tech-rich Nasdaq Composite Index lost 74.64 (1.49 per cent) to 4,922.82.