Nasdaq turns positive boosted by big-cap tech
Dow industrials and S&P 500 had fallen 1 pct each at open.
The Dow Jones industrial average fell 16.65 points, or 0.25 percent, to 6,610.29. The Standard & Poor's 500 Index dropped 0.15 points, or 0.02 percent, to 683.23. The Nasdaq Composite Index gained 5.05 points, or 0.39 percent, to 1,298.90.
(Reporting by Rodrigo Campos; Editing by James Dalgleish)