Wall Street ends flat on late comeback

U.S. stocks staged a late comeback to end flat on Tuesday despite disappointing earnings from blue-chips including 3M and Johnson & Johnson.

The Dow Jones industrial average (.DJI) dipped 3.33 points, or 0.03 percent, to 11,977.19. The S&P 500 (.SPX) edged up 0.34 point, or 0.03 percent, to 1,291.18. The Nasdaq Composite (.IXIC) gained 1.70 points, or 0.06 percent, to 2,719.25.