U.S. markets closed down more than 1 percent Wednesday ending a day that started with a slump over chaos in China's markets and intensified when the New York Stock Exchange halted trading for about 3.5 hours because of a "technical outage."

At the close on Wall Street, the Dow Jones industrial average was down nearly 261.5 points, about 1.5 percent, at 17,515.4. The Standard & Poor's 500 gave up 34.7 points, about 1.7 percent, to 2,046.7, and the Nasdaq had fallen 87.7 points, about 1.8 percent, to 4,909.8.

advertisement | advertise on newsday

Stocks fell 6 percent in Shanghai despite the Chinese government's latest efforts to shore up equities. Chinese stocks have plunged in the last month but are still up 70 percent over the past year.

United Continental Holdings, parent of United Airlines, ended the day down $1.49, about 2.7 percent, at $58.82. United grounded flights citing computer problems. The grounding, which stated about 8 a.m., ended before 10:30 a.m.

Reports from Bloomberg News and The Associated Press were used in this story.