U.S. stocks fell on Wednesday as investors were discouraged after Federal Reserve Chairman Ben Bernanke said the U.S. economy faces unusually uncertain prospects.

In remarks to the Senate Banking Committee, Bernanke said the Fed was ready to take further steps to bolster growth if needed, adding to investor worries about a sluggish recovery from recession.

To some degree, any type of (Fed) aid would be a strong signal that things are worse than what we think, said Nick Kalivas, senior equity index analyst at MF Global in Chicago.

The Dow Jones industrial average <.DJI> lost 117.38 points, or 1.15 percent, to 10,112.58. The Standard & Poor's 500 Index <.SPX> fell 13.56 points, or 1.25 percent, to 1,069.92. The Nasdaq Composite Index <.IXIC> dropped 28.27 points, or 1.27 percent, to 2,194.22.

Stocks fell further despite recent strong corporate results, including those of some major banks and technology bellwether Apple Inc , he said.

The market reaction is a little puzzling and indicative of the general caution that is on investors' minds, Kalivas said.

Shares of Wall Street firm Morgan Stanley jumped 7.3 percent to $27.07 after reporting higher-than-expected profit. Wells Fargo & Co rose 1.4 percent to $26.69 after its results.

Weighing on the Nasdaq were shares of Internet company Yahoo , down 8.4 percent at $13.93 a day after it posted revenue that missed Wall Street's estimates.

(Reporting by Rodrigo Campos; Additional reporting by Leah Schnurr; Editing by Kenneth Barry)