Stocks were headed for their worst day in a month Wednesday after the Federal Reserve signaled that it may be less willing to provide more stimulus to the U.S. economy.
The Fed's policy makers were encouraged by recent reports of job growth in the U.S. and seemed more willing to allow the economy to move forward on its own.
The Fed's signal came at a time when investors have become increasingly worried about the global effect of a recession in Europe and the ability of countries there to make large debt payments that are coming due.
"The punch bowl is being taken away by the Fed and the ECB and the markets don't like these punch bowls being taken away," said Doug Cote, chief market strategist with ING Investment Management based in New York. "But it's all part of getting back to normal. It's a sign that we don't need artificial stimulus, so I think the selloff is temporary."
The declines in US stocks were broad. Nine of the 10 industry groups in the S&P 500 index fell.
Minutes from the Fed's last meeting, released late Tuesday, started a sell-off that began in the U.S. and extended overseas.
Ever since the financial crisis and deep U.S. recession, governments have worked actively to prop up economies damaged by the global downturn.
The government stimulus is one of the key reasons behind large market rallies from the lows they hit around three years ago.
Central banks around the world, notably the Fed, have provided big injections of money into the financial system.
There have been some hopes recently that the Fed would authorize another bond-buying program, which keeps rates low and pumps money into the financial markets, boosting stocks and commodities.
The dollar rose and commodities prices fell sharply. Gold plunged $47, or 2.8 percent, to $1,625 an ounce. Silver fell 5 percent, copper fell 2.4 percent and crude oil dropped 1.2 percent. The stocks of materials and mining companies fell in response.
Markets were also lower in Europe following weak demand at an auction for Spanish government debt. Germany's DAX fell 2.2 percent and France's CAC-40 fell 2.1 percent .
Spain has become the latest point of worry for investors after Greece received its second bailout from international lenders.
Last week Spain announced austerity measures which will likely slow down its economy further and worsen its 23 percent unemployment rate, the highest among the countries that use the euro.
That concern was evident in the bond markets. The yield on Spain's 10-year bond spiked 0.20 percentage point to 5.61 percent after the country's borrowing costs rose sharply in a bond auction, a signal that investors' confidence in the Spain's finances is weakening.
—AP and Reuters contributed most of the reporting in this story.