Wall St ends 3-day rally

U.S. stocks ended lower overnight in thin trading amid ongoing concerns over euro zone debt crisis.
The Dow Jones Industrial Average erased 27.02 points, or 0.21 per cent, to close at 12,938.67 

The S&P 500 index fell 4.55 points, or 0.33 per cent to close 1,357.66.

Most key S&P sectors finished lower,led by banks shares,while energy stocks gained.
The Nasdaq slid 15.40 points, or 0.52 per cent at 2,933.17.