(REUTERS) -- Stock erased early gains and turned negative after weaker-than-expected data on Midwest business activity and consumer confidence.

The Dow Jones industrial average dropped 6.66 points, or 0.05 percent, to 12,647.06. The Standard & Poor's 500 Index lost 0.55 points, or 0.04 percent, to 1,312.46. The Nasdaq Composite Index shed 0.78 points, or 0.03 percent, to 2,811.16.

(Reporting By Chuck Mikolajczak; editing by Jeffrey Benkoe)