Californian mortgage lender IndyMac Federal Bank has been bought by a group of private equity investors for $13.9bn (£9.5bn).

The seven-member consortium, which is led by private equity firm Dune Capital and includes billionaire George Soros and Michael Dell, founder of computer giant Dell Inc, brought IndyMac through a partnership called IMB Management.

IndyMac, which specialises in loans made with little down payment or proof of assets, underwrote loans in areas with rapidly escalating house prices in California and Florida, and was seized by the government in July after a run on the bank.

Once the deal closes, the investment group will inject $1.3bn of new capital into the bank.