The S&P 500 and Nasdaq indexes turned negative on Wednesday, with the Nasdaq falling 1 percent as discouraging corporate results preceded a meeting of European leaders to tackle the region's debt crisis.

Stocks had opened higher on bullish comments from Boeing Co , but shares lost their gains within the first 90 minutes. The Nasdaq was pressured by , which late Tuesday issued a weak outlook.

The Dow Jones industrial average <.DJI> was up 16.24 points, or 0.14 percent, at 11,722.86. The Standard & Poor's 500 Index <.SPX> was down 5.02 points, or 0.41 percent, at 1,224.03. The Nasdaq Composite Index <.IXIC> was down 27.92 points, or 1.06 percent, at 2,610.50.

(Reporting by Ryan Vlastelica; Editing by Kenneth Barry)