The rapid fall of Stanley O'Neal from the helm of Merrill Lynch has left investors wondering who else in the banking industry may pay a price for the U.S. subprime mortgage crisis.

O'Neal's downfall leaves Citigroup's Charles Prince, Bear Stearns' James Cayne and
Countrywide Financial's Angelo Mozilo among the prominent U.S. chief executives under fire for failing to avoid losses from mortgages and this summer's seizing up of credit markets.