The number of U.S. workers filing new claims for jobless benefits fell last week, but the prior period's figure was revised up, according to a government report on Thursday that highlighted the fragility of the labor market.

Initial claims for state unemployment insurance benefits fell 4,000 to a seasonally adjusted 570,000 in the week ended August 29 from an upwardly revised 574,000 the prior week, the Labor Department said.

Analysts polled by Reuters had forecast new claims falling to 560,000 last week from a previously reported 570,000.

A Labor Department official described the report as straight-forward.

The four-week moving average for new claims, considered a better gauge of underlying trends as it irons out week-to-week volatility, rose 4,000 to 571,250 last week.

The number of people collecting long-term unemployment benefits rose 92,000 to 6.23 million in the week ended August 22, the latest week for which the data is available, indicating that companies remained reluctant to expand payrolls, despite an improvement in the economy's outlook.

That was well above market expectations for 6.12 million.

However, the four-week moving average fell 27,250 to 6.22 million. The insured unemployment rate, which measures the percentage of the insured labor force who are jobless, inched up to 4.7 percent in the week ended August 22 from 4.6 percent the prior week.

(Reporting by Lucia Mutikani; Editing by Andrea Ricci)

Unemployment