* U.S. weekly new jobless claims fall sharply last week
* Number of workers on long-term unemployment aid rises
* White House says labor market to improve slowly
* Some retailers report sales less steep than expected
By Lucia Mutikani
WASHINGTON, Aug 6 (Reuters) - The number of laid-off U.S. workers submitting new claims for jobless benefits fell sharply last week, fanning hopes the fragile labor market was on the mend and that the broader economy was stabilizing.
Initial claims for state unemployment insurance fell 38,000 to a seasonally adjusted 550,000 in the week ended Aug. 1, the Labor Department said on Thursday, beating market expectations for a drop to 580,000.
In a sign that the trend was firmly toward a moderation in the pace of layoffs, the four-week moving average for new claims fell 4,750 to 555,250 in the week ended Aug. 1.
The four-week moving average is considered a better gauge of underlying trends as it irons out week-to-week volatility. The moving average has declined for six consecutive weeks.
However, the number of people collecting long-term unemployment benefits rose by 69,000 to 6.31 million in the week ended July 25, though the four week moving average declined for four straight weeks.
Analysts said the report, which followed data on Wednesday showing steeper private-sector job cuts and declining non-manufacturing employment in July, restored optimism that the labor market was starting to heal.
"The U.S. labor market is on the mend. This corroborates our view that the pace of layoffs has slowed down noticeably," said Harm Bandholz, an economist at Unicredit Markets & Investment Banking in New York.
Top White House economic adviser Christina Romer cautioned, though, that economic recovery will be painful and that Friday's widely-watched report on July unemployment likely will show hundreds of thousands more jobs were lost.
U.S. stocks opened higher <.DJI>, but better sentiment over
the jobless claims report quickly fizzled as biotech shares
dropped following the downgrading of Celgene Corp
The jobless claims data, came ahead of the release of July's non-farm payrolls report, and may have signaled the 20-month-old recession was winding down, analysts said.
"The claims data are another sign that the recession could be behind us," said Kevin Flanagan, fixed income strategist for Global Wealth Management at Morgan Stanley in Purchase, New York.
"I am optimistic that a recovery is in the process of beginning, but we will need to see continued improvement in claims going through (below) the 500,000 level before the consumer is willing to come on board and be part of the recovery," he added.
A Reuters survey forecast that Friday's U.S. Labor Department report will show 320,000 workers lost their jobs in July, the least for any month since September when employers cut 321,000 jobs.
But the jobless rate may climb to 9.6 percent -- the highest since June 1983 -- from 9.5 percent in June, as employers remain reluctant to hire because of subdued demand.
ECONOMY STABILIZING
Romer, who chairs the White House Council of Economic Advisers, said on Thursday the U.S. government's $787-billion stimulus program was stabilizing the economy despite "unacceptable" job losses that may continue for some time.
"Unfortunately, even once GDP (gross domestic product) begins to grow, it will likely take still longer for employment to stop falling and begin to rise," she said. [ID;nN06315673]
Analysts said the sharp drop in jobless claims applications last week was more evidence that employers had cut way too many jobs as the economy sank in the first quarter.
"Business overdid things earlier in the year. The huge layoffs we had were not justified ... we are anticipating that we will see (jobless claims) numbers like this frequently going froward," said Milton Ezrati, senior economist at Lord Abbett in Jersey City in New Jersey.
Labor market weakness is casting a shadow over the economy's recovery prospects from the worst recession in over 60 years as high unemployment exerts pressure on incomes, severely curtailing households' spending capacity.
Consumer spending is the main driver of U.S. economic activity and there are some signs that shoppers may be coming back to the malls.
Some U.S. retailers on Thursday reported sales declines for July were not as steep as expected, although same-store sales were likely to fall for an 11th straight month. For details see [ID:nN06253715]
(Additional reporting by David Lawder in Washington, John Parry in New York and Jessica Wohl in Chicago)