* Yellen says near-zero funds rate could persist for years
* Sees core inflation falling to about 1 pct
* Bullard says Fed needs to outline clear exit strategy
By Ros Krasny
SAN FRANCISCO, June 30 (Reuters) - Top Federal Reserve officials said on Tuesday the central bank should not rush to raise interest rates or remove other accommodative policies as soon as the U.S. economy climbs out of recession.
In fact, given prospects for a very slow recovery marked by high unemployment, the Fed's key interest rate could stay near zero for years, said Janet Yellen, President of the San Francisco Fed.
"It's not outside the realm of possibilities that the fed funds rate could stay at zero for the next couple of years," Yellen told reporters after a speech in San Francisco.
In contrast to some of her colleagues, Yellen debunked worries that the United States would be driven into high inflation by the Fed's accommodative policies.
Indeed, Yellen said core inflation, stripped of volatile food and energy prices, could fall toward 1 percent in the next year -- well below her preferred level of 2 percent.
"The predominant risk is that inflation will be too low, not too high, over the next several years."
Yellen said she was baffled by fears of a "cataclysmic" surge in inflation, and said market forecasts for an imminent rate increase were "jumping the gun".
Short-term interest rate futures, which measure market sentiment toward Fed policy, show about a 50-percent chance for a rate increase before the end of 2009. The fed funds rate has been in a range of zero to 0.25 percent since December.
"History shows us that this kind of (inflationary) concern has caused central banks, both ourselves and Japan, to tighten too early," Yellen said.
"I do not believe that there is a real threat of high inflation in the current situation."
FIND YOUR NEAREST EXIT
Earlier, James Bullard, President of the St Louis Fed, also said that the bank's very accommodative monetary policy will remain in place for an extended period.
A premature exit could thwart the recovery that most forecasters now anticipate, Bullard said at a Global Interdependence Center event at the Philadelphia Fed.
Still, Bullard, one of the Fed's more hawkish policymakers, warned of the need for a defined exit strategy by the Fed to control inflation expectations.
Selling Fed-held assets was probably the most likely way it would choose to go, Bullard said.
"Without an exit strategy, expectations of high inflation may develop," Bullard said at an event held at the Philadelphia Fed. "If expectations of inflation feed into today's long-term yields, those yields will rise today and hamper recovery prospects."
Yellen agreed to the extent that rising rates could hurt the "still very sick" housing markets by pushing up mortgage rates.
But in general, she played down the idea that the Fed needed to do more to specify what its strategy will be to reverse its accommodative monetary stance.
The Fed "certainly has the means to unwind the stimulus when the time is right," said Yellen, a voting member of the Federal Open Market Committee in 2009. Bullard will vote on the FOMC in 2010.
WISDOM AND PATIENCE
Yellen cited a need to not repeat the policy blunder committed by the Fed during the Great Depression.
In 1936, following two years of robust recovery, the Fed tightened because it was worried about large quantities of excess reserves in the banking system -- and in 1937 the economy plunged back into a deep recession.
"Let this not be another 1937, but a time when policymakers have the wisdom and patience to nurse the economy back to health."
Recovery, when it occurs, would be "frustratingly slow," with the unemployment rate unlikely to return to normal for several years, she said.
With the jobless rate last reported at 9.4 percent for May, Yellen said she would be "thrilled" to see unemployment down to 6 percent in the next few years, and said achieving that goal demanded the Fed use "every bullet" in its arsenal.
"What could be clearer than the fact that right now we need more demand -- not less -- to offset the slack in labor and product markets?"
INDEPENDENCE AT RISK?
Bullard and Yellen diverged on potential fallout from the Fed's unprecedented actions to reverse the financial crisis with a series of taxpayer funded bailouts of large financial institutions.
"If that leads to some sort of erosion, or even the appearance of an erosion, of the independence of the Fed, I think that could be very counterproductive," Bullard said.
Fed Chairman Ben Bernanke endured a hostile congressional grilling last week over the Fed's role in Bank of America's purchase of Merrill Lynch. Lawmakers have demanded Fed emails and questioned its accountability.
Yellen said congressional scrutiny was understandable given the Fed's "extraordinary" actions, but that she did not think fundamental support for the Fed's mandate was under threat. (Editing by Jan Dahinten)