U.S. stocks opened sharply higher on Thursday following a string of stronger-than-expected quarterly corporate profits, a broker upgrade for General Electric Co and fresh signs that the economic slump is waning.

The Dow Jones industrial average <.DJI> was up 93.34 points, or 1.03 percent, at 9,164.06. The Standard & Poor's 500 Index <.SPX> was up 12.72 points, or 1.30 percent, at 987.87. The Nasdaq Composite Index <.IXIC> was up 23.69 points, or 1.20 percent, at 1,991.45.

(Reporting by Edward Krudy; Editing by Padraic Cassidy)