Stocks turned positive shortly after the open on Tuesday, lifted by gains in shares of resource companies and as a broker upgrade gave a boost to BlackBerry maker Research In Motion Ltd .

Data due at 10 a.m. is expected to show U.S. manufacturing expanded in August.

The Dow Jones industrial average <.DJI> gained 19.35 points, or 0.20 percent, to 9,515.63. The Standard & Poor's 500 Index <.SPX> gained 2.68 points, or 0.26 percent, to 1,023.30. The Nasdaq Composite Index <.IXIC> gained 11.99 points, or 0.60 percent, to 2,021.05.

(Editing by Padraic Cassidy)