Dow, S&P 500 turn negative

The Dow and S&P 500 turned negative while the Nasdaq cut its gains in late morning on Tuesday, with materials and energy shares leading declines on the S&P.

The Dow Jones industrial average was down 44.15 points, or 0.33 percent, at 13,470.96. The Standard & Poor's 500 Index was down 0.17 point, or 0.01 percent, at 1,444.32. The Nasdaq Composite Index was up 6.60 points, or 0.21 percent, at 3,120.13.