(Updates to open)
NEW YORK, July 31 (Reuters) - U.S. stocks opened higher on Tuesday after General Motors Corp. further boosted confidence about corporate earnings.
The Dow Jones industrial average was up 45.11 points, or 0.34 percent, at 13,403.42. The Standard & Poor's 500 Index was up 6.15 points, or 0.42 percent, at 1,480.06. The Nasdaq Composite Index was up 23.04 points, or 0.89 percent, at 2,606.32.