JP Morgan, the US bank that is believed to have a struck a preliminary US$13 billion settlement with authorities over various legal claims connected to the sale of mortgage-backed securities in the run-up to the financial crisis, could face an additional bill of nearly US$6 billion ($7.1 billion) as it attempts to strike a deal with a group of institutional investors seeking to recover some of their losses.

No formal agreement is believed to have been reached, but a source familiar with the talks told the Reuters news agency that the final agreement could be worth up to US$6 billion as JP Morgan looks to settle with the group that includes money managers BlackRock.

The legal headaches have revived the debate over whether JP Morgan is too big and too complex a business, and refocused attention on Jamie Dimon, the bank's combative chief executive, who thus far has seen off demands that he should give up his dual role as chairman.

- Independent