Bank of America says its third-quarter profits have slumped by 50%.
The bank says companies have struggled to repay debts following the US terror attacks.
Bank of America suffered bad debts and low investment gains despite recent rate cuts.
The bank revealed third-quarter net income of £580m, down from £1.7bn.
Bad debt, for which the company does not expect repayment, rose to £1.3bn from £300m a year ago.
Revenues rose to £6bn as low US interest rates helped loan growth.
The Federal Reserve has reduced interest rates nine times so far this year in efforts to prevent a recession.
The bank also recorded a £276mn drop in investment gains.
Many banks' businesses were hit when US stock markets closed for four days following the September 11 attacks.