The Nasdaq turned negative in choppy trade on Monday, and the Dow and S&P 500 indexes extended losses, as caution about potential fallout from Europe's sovereign debt problems weighed on sentiment.

Bank of America Corp dropped 2.8 percent to $14.57, while JPMorgan Chase & Co declined 1.5 percent to $37.71. Microsoft Corp , off nearly 1 percent, was the top drag on Nasdaq.

The Dow Jones industrial average <.DJI> was down 37.10 points, or 0.37 percent, at 9,975.13. The Standard & Poor's 500 Index <.SPX> was down 1.37 points, or 0.13 percent, at 1,064.82. The Nasdaq Composite Index <.IXIC> was up 0.83 points, or 0.04 percent, at 2,141.95.

(Reporting by Ellis Mnyandu)