NEW YORK, Jan 12 (Reuters) - Banks led U.S. stock indexes higher at the open o~ Wednesday after a healthy bond sale in Portugal and signs of strength in the U.S. banking sector.
The Dow Jones industrial average gained 57.52 points, or 0.49 percent, to 11,729.40. The Standard & Poor's 500 Index rose 6.96 points, or 0.55 percent, to 1,281.44. The Nasdaq Composite Index added 11.98 points, or 0.44 percent, to 2,728.81.