U.S. recession to last well into 2010: Feldstein

BEIJING (Reuters) - The United States will probably continue to be in recession well into next year, potentially prompting the need for another large fiscal stimulus package, prominent economist Martin Feldstein said on Tuesday.

U.S. President Barack Obama signed into law last month a $787 billion fiscal stimulus plan, comprising $287 billion in temporary tax breaks and $500 billion in public spending.

Feldstein, a Harvard University professor who is a member of Obama's Economic Recovery Advisory Board, told Reuters that the existing stimulus package would offset only a relatively small fraction of the likely fall in consumer spending, exports and residential construction.

"I'm afraid that the economy will continue to slide down well into next year," Feldstein, a former head of the National Bureau of Economic Research, said in an interview in Beijing where he was attending a conference.

"I don't know when it will end, but the forecasts that it'll end later this year I think are too optimistic," he said of the recession.

"The fiscal stimulus is just not large enough to offset the downward pressure that comes from reduced consumer spending. So unless somehow fixing the financial markets is enough to offset that, which I very much doubt, I think there will be a need for another fiscal stimulus package at some point."

He said that the size of a potential future package would depend on how effective it was at stimulating the economy, but that it would probably have to be on the same order of magnitude as the existing one, if not larger.

(Reporting by Jason Subler and Zhang Shengnan; Editing by Nick Macfie)