New U.S. claims for unemployment benefits rose more than expected last week as harsh weather conditions in some parts of the country kept workers at home and caused a backlog in the processing of claims, a government report showed on Thursday.

Initial claims for state unemployment benefits jumped 51,000 to a seasonally adjusted 454,000, the highest since late October, the Labor Department said. That was the largest weekly increase since September 2005.

Economists polled by Reuters had expected claims to be little changed at 405,000.

The prior week's figure was revised slightly down to 403,000 from the previously reported 404,000.

A Labor Department official said four states had reported an increase in claims that was due to snow. In addition, he said, seasonal volatility also affected the data.

Still, the four-week moving average of unemployment claims -- a better measure of underlying trends, rose 15,750 to 428,750 last week, implying a gradual labor market recovery that could compel the Federal Reserve to complete its $600 billion bond buying program aimed at bolstering the economy. (Reporting by Lucia Mutikani, Editing by Andrea Ricci)