Mohamed El-Erian, CEO of money management titan Pimco, gives Federal Reserve Chairman Ben Bernanke and Treasury Secretary Tim Geithner an “A” for effort in fighting the credit crisis.

But they merit just a “B” for results, El-Erian told Bloomberg.

“They’ve been imaginative, they’ve been bold, they’ve been willing to take risks. On outcome it’s a ‘B.’”

The Fed has pushed short-term interest rates down to nearly zero and doubled its balance sheet through purchases of Treasuries and mortgage securities and through various loan programs.

The Treasury just joined with nine private investment firms to eventually buy up to $40 billion of the toxic assets weighing down bank balance sheets (the Public-Private Investment Program).

“We’re in a phase of policy experimentation. We’ve never seen this,” El-Erian says.

El-Erian compares Bernanke and Geithner to pilots trying to steer a plane through a storm.

“Our assumption is that the pilots know what to do,” he says.

If the cockpit door was open, “we would see the pilots banging on the instruments because they’re getting readings they’ve never seen before.”

As the White House begins to consider appointing Bernanke to another term, many others have expressed views about him similar to El-Erian’s.

"Bernanke's leadership during this financial crisis was outstanding, but not flawless," economist Scott Anderson of Wells Fargo told The Wall Street Journal.