THE number of workers in the United States filing new applications for jobless insurance tumbled last week by a surprisingly large amount to the lowest level in more than a year, according to government data yesterday that signaled the battered labor market is improving.

Initial claims for state unemployment benefits slid to a seasonally adjusted 466,000 in the week ended Saturday, from a revised 501,000 in the prior week, the Labor Department said. Seasonal adjustments turned a smaller-than-anticipated unadjusted rise in claims into a drop, a department economist said.

It was the fourth consecutive week of declines in seasonally adjusted claims, and marked a steady march lower from a recent peak of 674,000 in late March.