Democrats in both the House and Senate complained that the measure fell short of what was needed, but Bush said its enactment "should bring some comfort to those of our fellow citizens who need extra help during the time in which they try to find a job."

The measure extends a federal program that provides 13 weeks of benefits for the unemployed who have exhausted their 26 weeks of state aid. The federal program lapsed on Dec. 28, but the Labor Department said the flow of benefits would continue uninterrupted if legislation were signed into law by Thursday.

Officials said an estimated 750,000 people are immediately affected, plus an additional 1.6 million who are expected to become eligible before the extension expires on June 1.

The president placed his signature on the $7.2 billion bill a few hours after it cleared the House on a vote of 416-4. The Senate passed the measure Tuesday on a voice vote.

The lopsided votes masked a politically charged debate in which Republicans claimed credit for helping the jobless as their first order of business in the new Congress, and Democrats accused the GOP majority of acting grudgingly.

"It is important to note that the first piece of important legislation ... helps American families by extending unemployment insurance," said Speaker Dennis Hastert, R-Ill.

Democrats failed in an attempt to win approval for a more generous bill, and said they were underwhelmed by the GOP-crafted measure.

"Not just 13 weeks, we need 26 weeks at least," said Democratic Rep. David Scott, a first-term Georgian who was sworn into Congress on Tuesday.

Apart from the unemployment measure, the House unanimously approved legislation during the day granting a 3.1 percent pay raise to federal judges, the same boost that other government employees received on Jan. 1.

GOP leaders also were working for passage of legislation to keep the federal government in operation through Jan. 31. Current spending authority for many departments and agencies expires on Saturday.

Bush signed the unemployment bill at a meeting with top Republican and Democratic leaders of the House and Senate, his first since the new Congress convened.

The unemployment issue was a blend of old and new business for lawmakers.

Congress adjourned late last year without passing an extension of the federal program, triggering angry protests from Democrats at the time.

At the same time, Rep. Bill Thomas, the California Republican who chairs the House Ways and Means Committee, said the debate was a precursor to a struggle over Bush's proposals to stimulate the economy.

Democrats have already criticized the proposals as heavily tilted toward the rich.

Speaking of Democrats who opposed the jobless aid bill on the floor during the day, Thomas said, "I'm quite sure my colleagues will be opposed to the proposals to stimulate the economy as well. So those will be future battles."

But for now, he said, "We're in a position of having the president sign a bill tomorrow or not sign a bill tomorrow."

Democrats said their proposals - an additional 13 weeks of benefits on top of the current 13 - could easily be accepted by the Senate and signed into law by the president. The change would help the estimated one million unemployed who have already exhausted their extra 13 weeks of benefits. The bid to alter the legislation failed on a vote of 224-202.

"The Republican Party does not care about those million unemployed," contended Rep. Jim McDermott, D-Wash., "because you have the presidency, you have the Senate and you have the House."

In fact, the measure that was sent to Bush's desk was far more generous than Thomas and other GOP leaders were willing to approve late last year, and more than even the Democrats were proposing in November.

The House approved a five-week extension in federal benefits last fall, but only for the jobless in three high-unemployment states.

In the Senate, Hillary Clinton, D-N.Y., and Don Nickles, R-Okla., reached agreement on an alternative at the time that would have extended the expiring program in all 50 states, through March 31.

Thomas and other House GOP leaders spurned the measure, though, and Congress adjourned.

In the Senate, newly elected Majority Leader Bill Frist, R-Tenn., sought passage of a five-month extension as the first order of business when the Senate convened on Tuesday. But by then, Democrats in both houses, noting that unemployment has continued to rise, decided to press for additional benefits for jobless people who have already exhausted their 13 weeks of benefits.

"Frankly, it's the least they can do," said House Democratic Leader Nancy Pelosi of California. "But we can do better."

But Texas Rep. Tom DeLay, House majority leader, said, "nothing is good enough" for Democrats. "I would venture to guess that they would have unlimited unemployment compensation so somebody could stay out of work for the rest of their lives."

Voting against the bill Wednesday were Republican Reps. Jeff Flake of Arizona, Jeff Miller of Florida, Ron Paul of Texas and Scott Garrett of New Jersey.