Stocks added to gains in afternoon trading on Wednesday, pushing the Dow and S&P 500 indexes briefly up 1 percent, led by an advance in energy shares as oil prices rose.

The Dow Jones industrial average <.DJI> was up 85.55 points, or 0.93 percent, at 9,303.49. The Standard & Poor's 500 Index <.SPX> was up 8.85 points, or 0.89 percent, at 998.52. The Nasdaq Composite Index <.IXIC> was up 13.40 points, or 0.69 percent, at 1,969.32.

(Reporting by Caroline Valetkevitch; Editing by Jan Paschal)