Initial claims for state unemployment benefits rose 36,000 to a seasonally adjusted 482,000 in the week ended January 16, the Labor Department said, rising for a third straight week.
Economists polled by Reuters had forecast claims dipping to 440,000 from a previously reported 444,000. The weekly claims data covers the survey week for the Labor Department's January payrolls report, which is scheduled for release February 5.
A Labor Department official said the rise in claims was administrative rather than economic as claims that were not processed over the holidays were now being attended to.
In addition, because of Monday's Martin Luther King holiday, some states had failed to meet the deadline to submit their estimates, resulting in the department having to make estimates for some states.
There is a bit of a backload from the prior weeks. There were more claims than expected, it's not an economic thing, but an administrative thing, the official said.
U.S. stock index futures fell on the data, while Treasury debt prices pared losses.
The rise is statistical noise and it won't be big for the market, said Kevin Caron, market strategist at Stifel, Nicolaus & Co. in Florham Park, New Jersey.
The four-week moving average for new claims rose 7,000 to 448,250 last week, snapping a 19-week declining trend. The four-week moving average is viewed as a better measure of underlying trends as it levels out week-to-week volatility.
Labor market weakness remains a major obstacle to the economy's recovery, which started in the third quarter of 2009 following the longest and deepest downturn since the 1930s.
The number of workers still collecting benefits after an initial week of aid fell 18,000 to 4.6 million in the week ended January 9, the lowest since January 2009. This was in with market expectations.
So-called continuing claims have declined for five weeks and are below their peak of 6.9 million in June. There were 5.9 million receiving extended benefits under special programs in the week ended January 2.
The insured unemployment rate, which measures the percentage of the insured labor force that is jobless, was unchanged at 3.5 percent.
(Reporting by Lucia Mutikani; editing by Neil Stempleman)