The number of Americans filing new claims for unemployment benefits unexpectedly fell last week, indicating the jobs market was on solid footing even as the economy struggles to regain momentum after abruptly slowing in the first quarter.

Other data on Thursday showed that a strong dollar and lower oil prices suppressed producer inflation in April. That together with signs of modest growth early in the second quarter suggest the Federal Reserve will probably not raise interest rates until later in the year.

Initial claims for state unemployment benefits slipped 1,000 to a seasonally adjusted 264,000 for the week ended May 9, the Labor Department said on Thursday, within a whisker of a 15-year low reached two weeks ago.

They have been below 300,000, a threshold associated with a strengthening labor market, for 10 straight weeks. Economists polled by Reuters had forecast claims rising to 275,000.

The four-week moving average of claims, considered a better measure of labor market trends as it irons out week-to-week volatility, fell 7,750 to 271,750 last week. That was the lowest level since April 2000.

U.S. stock index futures added to gains after the data, while prices of U.S. Treasuries edged up. The U.S. dollar extended losses against a basket of currencies.

The claims data underscored the dilemma the U.S. central bank faces. Policymakers believe the economy is poised to strengthen and the labor market appears to be tightening, but surprisingly soft growth and subdued inflation pressures are complicating their plans to lift rates.

The Fed, which has a 2 percent inflation target, has kept its key short-term interest rate near zero since December 2008.

In a separate report, the Labor Department said its producer price index for final demand fell 0.4 percent last month, declining for the third time this year. The PPI increased 0.2 percent in March.

In the 12 months through April, producer prices fell 1.3 percent, the biggest year-on-year decline since 2010, after declining 0.8 percent in March.

Economists had forecast the PPI rising 0.2 percent last month and falling 0.8 percent from a year ago.

The economy barely grew in the first quarter, held back by a range of factors, including the dollar, bad weather and port disruptions. Retail sales and manufacturing data suggest that while activity is picking up, the pace remains modest.

A drop of 0.7 percent in the index for final demand goods accounted for more than 70 percent of the decline in the PPI last month. Energy prices fell 2.9 percent after rising 1.5 percent in March. Food prices fell for a fifth straight month.

The dollar, which has gained about 11 percent against the currencies of the United States' main trading partners since June, and lower energy prices are keeping inflation subdued.

Last month, the volatile trade services component, which mostly reflects profit margins at retailers and wholesalers, fell 0.8 percent after slipping 0.2 percent in the prior month.

A key measure of underlying producer price pressures that excludes food, energy and trade services ticked up 0.1 percent after rising 0.2 percent in March.