The U.S. government's $700 billion bailout program will ultimately produce an overall loss for taxpayers, a key auditor for the program said on Thursday.

The U.S. Treasury's Troubled Asset Relief Program will produce a negative return because some programs, such as $50 billion in housing subsidies, were not designed with any reasonable opportunity for a return to taxpayers, said Neil Barofsky, TARP's special inspector general.

Barofsky also told a forum sponsored by Bloomberg that he would audit the government's role and influence as a major shareholder in a number of private companies that received aid, including the role it played in General Motors Co.'s decision to scuttle an earlier deal to sell its Opel division in Europe.

(Reporting by David Lawder; Editing by Chizu Nomiyama)