Stocks extended losses on Monday, with the three major indexes falling more than 3 percent on worries about the sustainability of recent better-than-expected results from banks following Bank of America Corp's report of a big increase in troubled loans.

Banks led declines, with the KBW bank index <.BKX> down 12.6 pct.

The Dow Jones industrial average <.DJI> lost 253.44 points, or 3.12 percent, to 7,877.89. The Standard & Poor's 500 Index <.SPX> fell 32.59 points, or 3.75 percent, to 837.01. The Nasdaq Composite Index <.IXIC> dropped 59.51 points, or 3.56 percent, to 1,613.56.

(Reporting by Rodrigo Campos; editing by Jeffrey Benkoe)