U.S. stocks fell on Wednesday as quarterly results from three big U.S. banks raised concerns about the stability of the sector and analysts questioned IBM's profit forecast.

Morgan Stanley shed 1.1 percent to $30.81 after the company's quarterly profit missed expectations after accounting charges.

But Bank of America Corp added 0.6 percent to $16.41 as it said credit problems are beginning to stabilize but posted a wider-than-expected quarterly loss. The S&P Financial index <.GSPF> dropped 0.7 percent.

International Business Machines Corp fell 3.3 percent to $129.76 after at least three brokerages said its profit outlook is conservative and suggested a slowdown in earnings growth. IBM reporting stronger-than-expected quarterly profit on Tuesday.

The problem, with IBM as an example, is (the stock) ran up into this (earnings) report, so it's buy the sizzle and sell the steak, said Terry Morris, senior vice president and senior equity manager for National Penn Investors Trust Co in Reading, Pennsylvania.

The Dow Jones industrial average <.DJI> dropped 168.23 points, or 1.57 percent, to 10,557.20. The Standard & Poor's 500 Index <.SPX> fell 15.65 points, or 1.36 percent, to 1,134.58. The Nasdaq Composite Index <.IXIC> lost 39.96 points, or 1.72 percent, to 2,280.44.

The S&P 500 has seen an advance or decline of at least 1 percent in each of the last three sessions.

Wells Fargo & Co dipped 0.6 percent to $28.12 after the bank swung to a quarterly profit but loan losses increased.

In macroeconomic news, the government said December U.S. producer prices rose for a third straight month, increasing by 0.2 percent on a surge in food prices.

Housing starts in December fell unexpectedly, weighed down by a drop in construction activity for single-family dwellings, but new building permits rose 10.9 percent last month, according to Commerce Department data.

(Editing by Jeffrey Benkoe)

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