The S&P 500 briefly fell 2 percent as stocks extended losses late on Monday amid concerns about the euro-zone debt crisis and worries about the lack of progress in U.S. budget talks.

The Dow Jones industrial average <.DJI> was down 180.61 points, or 1.43 percent, at 12,476.59. The Standard & Poor's 500 Index <.SPX> was down 26.44 points, or 1.97 percent, at 1,317.36. The Nasdaq Composite Index <.IXIC> was down 62.61 points, or 2.19 percent, at 2,797.20.

(Reporting by Caroline Valetkevitch; Editing by Jan Paschal)