WASHINGTON — Federal Reserve Chairman Ben Bernanke today fended off congressional skepticism about expanding the Fed's duties to police big financial companies given the central bank's failure to catch problems that led to the financial crisis.

Bernanke also faced some grilling from the House Financial Services Committee about taxpayer bailouts of financial companies, slow moving efforts to curb home foreclosures and concerns about the Fed's track record in protecting consumers from abusive practices from lenders, credit card companies and other financial service providers.

"The Fed has made some big mistakes," said the panel's highest-ranking Republican, Spencer Bachus of Alabama. Letting the Fed become the financial supercop would be "just inviting a false sense of security" that would be shattered at taxpayers' expense, he warned.

Bernanke argued the Obama administration's proposal would be a "modest reorientation" of the Fed's powers, not a great expansion of them.

The Fed chief also sought to beat back an administration proposal that would create a new consumer protection regulator for financial services and strip some of those duties from the central bank.

Consumer groups and lawmakers have blamed the Fed for not cracking down early on dubious mortgages practices that fed the housing boom and figured into its collapse.

Bernanke sought to assure investors and Congress that the Fed will be able to reel in its extraordinary economic stimulus and prevent a flare up of inflation when the recovery is more firmly rooted.