Initial claims for unemployment benefits posted a rise of 36,000 to 447,000 from the previous week's revised figure of 411,000, the Labor Department said.
The U.S. economy has been in recession since last March so the weekly claims data are receiving special scrutiny for signs that declines in employment might be starting to level off.
The number of workers continuing to receive unemployment checks also surged, rising 42,000 to 3,715,000 for the week ending Dec. 22.
However, the four-week moving average, considered useful as a barometer since it smooths out weekly variations, posted a modest decline of 8,250 to 409,750 from the revised average of 418,000 in the prior week.
The Labor Department said there were no special factors contributing to the rise in the latest report but said that revisions such as the one to the initial claims number in the previous week can occur at this time of year because of the holidays.
The insured unemployment rate, a measure of the portion of the nation's work force that is receiving jobless benefits, was unchanged at 2.9 percent.