A consortium of private investors said they have completed their acquisition of banking operations of failed Pasadena thrift IndyMac Inc. and reopened the bank on Friday as OneWest Bank FSB.

OneWest Bank Group LLC, a group of private-equity investors led by Steven Mnuchin of Dune Capital Management LP, acquired IndyMac Inc.’s retail banking assets from the Federal Deposit Insurance Corp., which took over the bank in July after depositors made a run on the bank. The failure is expected to cost the FDIC $10.7 billion.

OneWest will operate as a regional bank, with 33 branches mostly in the Los Angeles area, and focus on deposits and mortgage lending in Southern California, OneWest Bank Group said.

OneWest also will operate the national mortgage banking business acquired from IndyMac and continue to modify mortgages in accordance with the program created by the FDIC. OneWest also acquired and will continue to operate Financial Freedom, one of the nation’s largest reverse mortgage businesses.

As part of the deal, FDIC will share in future loan losses. OneWest will assume the first 20 percent of losses from borrowers who default but the agency will cover much of the rest.

“We appreciate the support of the FDIC and the Office of Thrift Supervision in completing this transaction, and we are committed to continuing our work with the FDIC and other government agencies to implement programs to help homeowners,” OneWest Bank Group Chief Exective Steven Mnuchin said in a statement. “OneWest will benefit from a strong capital position and support from a committed group of investors.”