JACKSONVILLE, Fla. — President Bush pledged yesterday to increase federal grants to financially strapped college students, though offering less than he once pledged in a nod to mounting budget constraints.

Speaking to a crowd at Florida Community College, Bush said he intended to increase the maximum Pell Grant from $4,150 this year to $4,550 over five years — a 12 percent increase that would cost $15 billion.

Pell Grants, the government's primary college aid for lower-income students, are received by 5 million students, who last year received from $400 to $4,050 based on need and cost.

Bush's promise was a retreat from his 2000 pledge to increase the maximum grant to $5,100.

"We've been down this road before," Sen. Edward Kennedy, D-Mass., said in a statement, adding that families with college-age children shouldn't "count their chickens before they hatch."

College-education expenses have been rising far beyond the nation's inflation levels for years. The average in-state tuition at public, four-year universities in 2004, for example, increased 10.5 percent to $5,132, according to the College Board. Overall inflation averaged about 2.0 percent from 2001 through 2003.

Bush's scaled-back promise reflected new budget realities in Washington, where the president is looking for ways to reduce a record $413 billion federal deficit. The federal government was running a surplus when Bush was campaigning in 2000.

A recession, the stock-market downturn, the Iraq war and the Bush-sponsored tax cuts have contributed to the turnabout.

The president, who has promised to cut the budget deficit in half by the time he leaves office, will call for tightened spending in a proposed 2006 budget that he plans to unveil Feb. 7. He said he would pay for larger Pell Grants with savings from better administration of federal student-loan programs.

He didn't offer details on how he planned to achieve the savings, but an aide said the list of cost-saving proposals included cutting government subsidies to lenders who provide student loans.

"We're confident that we can gradually reduce the subsidies, the excessive subsidies, in that program," White House spokesman Trent Duffy said. "It is a very profitable industry."

Democrats expressed concern that Bush also would take money from other education programs.

"My first instinct is to say 'Show me the money,' " said Rep. George Miller, D-Calif., the top Democrat on the House Education Committee. "The fact is that so often the administration proposes to increase spending in one account by reducing spending for critical education services in another account. If the president's plan would rob Peter to pay Pell, it would be unacceptable."

White House spokesman Scott McClellan declined to provide details on the 2006 budget, but said Bush was determined to meet his deficit-reduction targets.

"I think the American people recognize we can do much more with a little less," McClellan said aboard Air Force One.

Details on the Pell Grant program and college costs were provided by The Associated Press.