U.S. stocks fell on Thursday after the vast U.S. services sector unexpectedly shrank in November and as nervousness rose a day before the monthly payrolls data.

Stocks sold off going into the close, led by a slide in financials, as Bank of America Corp's massive equity offering spurred concerns that other banks could sell new shares and dilute existing shareholders' equity. The S&P financial index <.GSPF> ended down 2.1 percent.

However, shares of Bank of America, parent of the largest bank ranked by assets, ended up 0.7 percent at $15.76 on optimism that its plan to repay $45 billion of government bailout money will free the bank from government restrictions, especially on executive pay.

On the data front, the services sector index fell to 48.7, indicating that this huge component of the U.S. economy had experienced contraction last month, according to a report from the Institute for Supply Management.

The ISM data hurt sentiment a day before November's unemployment figures are released in an even more influential economic report.

Given ISM today, and given the rally of the last few days, it may be some nervousness ahead of tomorrow's unemployment number, said Kurt Brunner, portfolio manager at Swarthmore Group in Philadelphia, in reference to the malaise on Wall Street.

You'll probably see some deterioration in the unemployment rate. One would think you're going to get at least some improvement in the job losses, but it bears being a little cautious.

The Dow Jones industrial average <.DJI> dropped 86.53 points, or 0.83 percent, to end at 10,366.15. The Standard & Poor's 500 Index <.SPX> slipped 9.32 points, or 0.84 percent, to close at 1,099.92. The Nasdaq Composite Index <.IXIC> fell 11.89 points, or 0.54 percent, to finish at 2,173.14.

With the S&P 500 up 63 percent from a closing low on March 9, tolerance for disappointing data has worn thin as investors seek justification for stocks' lofty valuations.

A bright spot was provided by Comcast Corp , up 6.5 percent at $15.91 after the company struck a deal to buy a majority stake in NBC Universal from General Electric Co .

The transaction, once closed, will create a media superpower. for details GE shares shed 0.4 percent to $16 on the New York Stock Exchange.

Other data on Thursday showed that the number of U.S. workers filing new claims for unemployment benefits fell last week, according to a government report, while third-quarter

productivity was slightly less robust than previously thought, a third report said.

(Reporting by Caroline Valetkevitch; Additional reporting by Leah Schnurr; Editing by Jan Paschal)