Stocks extended losses on Wednesday, with the Nasdaq falling 1 percent, as investors pulled back after days of gains built on optimism built on expectations of progress on a resolution to the euro zone debt crisis.

The Dow Jones industrial average <.DJI> was down 78.60 points, or 0.65 percent, at 12,071.53. The Standard & Poor's 500 Index <.SPX> was down 10.50 points, or 0.83 percent, at 1,247.97. The Nasdaq Composite Index <.IXIC> was down 30.07 points, or 1.13 percent, at 2,619.49.

(Reporting By David Gaffen; Editing by James Dalgleish)