WASHINGTON — With the economy moving ahead and the nation's payrolls picking up a bit, Federal Reserve policy-makers on Tuesday boosted short-term interest rates for a third time this year — but left economists split about when the next increase might come.

Fed Chairman Alan Greenspan and his Federal Open Market Committee colleagues — the group that sets interest-rate policy — increased the target for the federal funds rate from 1.50 percent to 1.75 percent. The funds rate is the interest banks charge each other on overnight loans and is the Fed's primary tool for influencing economic activity.

Reacting to the Fed's decision, Wells Fargo said it was increasing the prime lending rate for many short-term consumer and business loans from 4.50 percent to 4.75 percent. Other commercial banks were expected to follow suit.

The Fed, explaining its unanimous decision, said the economy — which slowed earlier this year partly because of soaring energy prices — now "appears to have regained some traction." That echoed a comment Greenspan made to Congress earlier this month.

In another encouraging note, the Fed said, "Labor market conditions have improved modestly." That was a better assessment than the Fed offered in August, when it said job market improvements had slowed.

"The Fed is sending a message of relative comfort with the current condition of the economy," said Lynn Reaser, chief economist at Banc of America Capital Management. "They suggested we are pulling out of the soft patch."

On Wall Street, the Dow Jones industrials gained 40.04 points to close at 10,244.93.

The Fed's rate increase comes with Election Day just six weeks away. President Bush and his Democratic rival, John Kerry, hold widely divergent views of the health of the economy and the job market.

Incumbent politicians normally are unhappy if the Fed raises interest rates close to an election. Yet, some economists said that by raising rates, the Fed could be viewed as appearing comfortable about the pace of the economy's expansion, which could be seen as good for the Bush campaign.

Other economists said that if the Fed had dropped its gradual rate-raising approach and unexpectedly passed on a rate increase in September, it might have looked politically motivated.

"I think what they needed to do so close to the election is not stray from the path that they had set out," said Carl Tannenbaum, chief economist at LaSalle Bank. "Maintaining their course for rates is the wisest thing to do both economically and politically."

The Fed's rate-raising campaign began in June when the central bank ordered its first rate increase in four years. Since then, the Fed raised the rates in August and then Tuesday.

Fed policy-makers stuck to their view that future rate increases would be gradual because inflation is expected to remain relatively low. Inflation has eased in recent months despite the rise in energy prices, the Fed said.

Analysts believe the funds rate will rise to 2 percent by the end of this year. Economists, however, have mixed opinions on additional rate increases. Some believe the Fed will boost rates again on Nov. 10, then stand pat Dec. 14, its last meeting of the year. Others believe the Fed might take a breather at the November meeting but raise rates in December.

The economy is expanding and no longer needs the support of ultralow interest rates, economists said.

Even with the latest increases, both the funds rate and the prime rate remain low by historical standards. Before the Fed ordered its first rate increase of the year in June, the funds rate had been kept for a year at 1 percent, a 46-year low, to support the economy.

A series of 13 rate reductions from January 2001 to June 2003 left the funds rate at 1 percent as the Fed battled to help an economy staggered by a series of blows: a plunging stock market, the 2001 recession, terror attacks and two wars.