IndyMac Bancorp, one of the largest banks to fail as a result of the subprime mortgage crisis, is close to being sold to a consortium of private equity and hedge fund firms, people briefed on the matter told DealBook. The Federal Deposit Insurance Corporation, along with a team of former Lehman Brothers bankers who are now with Deutsche Bank, have been engaged in the sale process since federal regulators declared IndyMac insolvent in July and seized the company. The deal could be announced as soon as Monday, these people said. At the time, the collapse of IndyMac ranked as the second-largest failure in FDIC history and was quickly followed by near-failures and subsequent fire sales of banking giants Wachovia and Washington Mutual. The buyers include private equity firms J.C. Flowers & Company and Dune Capital Management and the hedge fund firm Paulson & Company, these people said.