Stocks skidded amid sliding oil prices and mixed earnings results after rising the three previous sessions.
The Dow Jones Industrial Average dropped more than 70 points after rising more than 75 points on Tuesday.
Walt Disney led the blue-chip average lower following disappointing earnings and revenue results delivered after the market closed on Tuesday. Disney's amusement parks were hurt by the disasters in Japan, and the poor performance of "Mars Needs Moms."
The Dow got some support from Intel, which jumped after the tech firm said Wednesday it would raise its cash dividend by 16 percent to 21 cents a share.
TheS&P 500 and the Nasdaq also fell. The CBOE Volatility Index, widely considered the best gauge of fear in the market, rose above 16.
Most key S&P 500 sectors declined, led by energy and materials, while consumer staples gained.
The energy sector was hurt by sliding prices for oil futures, which added to losses after the U.S. Energy Information Administration said crude inventories grew by 3.8 million barrels last week, which was more than expected. Gasoline futures also sank after news inventories rose by 1.3 million barrels, which was also more than expected.
U.S. light, sweet crude fell more than 2 percent to below $102 a barrel, while in London, Brent crudefell more than 2 percent to below $116.
Anadarko Petroleum ,Apache and ConocoPhillips were among energy stocks leading the sector lower.
Gold and silverfutures fell slightly, while the dollar rose against a basket of currencies.
AIG and the Treasury scaled back plans for share sale, and will now offer$9 billion in AIG stock.