Wall Street ends shortened session lower

MARKETS-USA-STOCKS:Wall Street ends shortened session lower

U.S. stocks closed lower in a shortened session on Monday as investors continued to worry that Congress would be unable to reach a deal to avert the "fiscal cliff."

The Dow Jones industrial average was down 51.76 points, or 0.39 percent, at 13,139.08. The Standard & Poor's 500 Index was down 3.49 points, or 0.24 percent, at 1,426.66. The Nasdaq Composite Index was down 8.41 points, or 0.28 percent, at 3,012.60.