Highlights:

* U.S. Steel Corp profit surges, stock rises 7 pct

* DuPont reports loss, trims 2009 forecast

* The Dow <.DJI> gains 39.27 points, or 0.48 percent, to 8,155.30. The S&P 500 Index <.SPX> rises 5.16 points, or 0.62 percent, to 841.73. The Nasdaq Composite <.IXIC> adds 10.19 points, or 0.68 percent, to 1,499.65.

(Reporting by Rodrigo Campos; Editing by James Dalgleish)