JPMorgan Chase is to take a charge of about $9bn - half as much again as its estimate - to clean up Bear Stearns' balance sheet and pay for redundancies and litigation arising from its cut-price takeover of the stricken investment bank.

Jamie Dimon, JPMorgan's chairman and chief executive, told a banking conference organised by UBS that the higher costs were driven by the losses suffered by Bear this year and the larger than expected amount of bad assets on its books.