Wall Street up for third straight day as energy rallies

NEW YORK (Reuters) - U.S. stocks extended a rally for a third day on Tuesday as sharp gains in oil prices lifted energy shares and traders factored in increased expectations for central bank stimulus.

The Dow Jones industrial average <.DJI> gained 72.43 points, or 0.56 percent, to end unofficially at 12,943.82. The Standard & Poor's 500 Index <.SPX> rose 8.51 points, or 0.62 percent, to finish unofficially at 1,374.02. The Nasdaq Composite Index <.IXIC> climbed 24.85 points, or 0.84 percent, to close unofficially at 2,976.08.

An S&P index of energy shares <.GSPE> rose 2.17 percent.

(Reporting by Chuck Mikolajczak; Editing by Jan Paschal)