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.