NEW YORK (AP) -- A warning from Fitch Ratings that large U.S. banks could be hit hard if Europe's debt crisis spreads sent stocks falling late Wednesday.

U.S. indexes were moving between small gains and losses before Fitch released its report around 3:15 p.m. Eastern time. The Dow was down 36 points with an hour of trading left, then plunged to end the day down 190.

Fitch, one of the three main credit ratings agencies along with S& P and Moody's, said U.S. banks could be " greatly affected" if Europe's debt crisis continues to spread beyond financially troubled countries such as Greece, Ireland and Portugal.

Large banks took a late dive. Bank of America Corp. and JPMorgan Chase & Co. each lost 3.7 percent. Goldman Sachs dropped 4.1 percent and Morgan Stanley 7.9 percent.