WASHINGTON (June 18, 2009)--Treasury Secretary Timothy Geithner was encountering some skepticism on Capitol Hill about the president's plan to transform the Federal Reserve into a super-regulator.

Some lawmakers are worried that the central bank isn't the best choice to keep an eye on firms considered so big and influential that their demise could hurt the economy.

Geithner was explaining the plan before two congressional committees Thursday.

It would give the Fed more authority, create a new consumer protection agency and bring unregulated sectors of the financial markets under government oversight.

Sen. Richard Shelby says it's not reasonable to expect the Fed or any other agency "to effectively play so many roles."

The Alabama Republican points out that the Fed also sets monetary policy, regulates banks and handles an array of other functions.

Some lawmakers have proposed that the job of overseeing large institutions be left to a council of regulators, not a single agency, but Geithner told the Senate Banking Committee, "You cannot convene a committee to put out a fire."