Interest rates on federal student loans will fall to a record low this summer, giving debt-burdened graduates what may be a last chance to save thousands of dollars by consolidating their loans, lenders said Monday.

By consolidating, borrowers will be able to lock in very low rates for their total debt for the life of a new loan.

The new rates, which will be available for one year beginning in July, are tied to Monday’s 91-day Treasury bill auction.

The rate on Stafford student loans now in repayment are expected to drop from 3.42 percent to 3.37 percent, lenders said. The rate on loans for students still in school or those in a grace period will fall from 2.82 percent to 2.77 percent.

Parents, too, get a break, with the rate on Federal Parent Loans for Undergraduate Students dipping from 4.22 percent to 4.17 percent.

These rates apply to loans made after July 1, 1998. Older loans will have slightly higher rates, experts said.

This is the fourth consecutive year that student loan rates have fallen, and these latest rates will be the lowest in the federal student loan program’s 39-year history, according to Sallie Mae, a student loan provider. When the program was launched in the 1960s, the rate was 6 percent.

Even if they don’t choose to consolidate, borrowers will automatically get the new federal loan rates for one year.

They can, however, lock in low rates by consolidating their loans, where existing loans are paid off and replaced with a single, fixed-rate loan.

Interest rates on consolidation loans can differ among borrowers. The formula uses a weighted average of the borrower’s existing loan rates and rounds it up to the nearest one-eight of 1 percent.

By consolidating newer loans, though, borrowers would secure a fixed rate of 3.75 percent, lenders said. The rate for those consolidating during the six-month grace period after graduation would be 2.875 percent.

Consolidating after the new rates take effect can save borrowers thousands of dollars. Some say there is no better time to consolidate.

“It’s fair to say we found the bottom of the interest rate market,” said Mark Brenner, executive vice president for College Loan Corp., a student loan provider in San Diego.

Another incentive to consolidate in the next year is that Congress is considering changing future consolidation loans from a fixed to a variable rate to save money. Uncle Sam pays a subsidy to lenders when student loan rates fall too low.

Some warnings about consolidation. You can only do it once, unless you go back to school and take out a new loan, said Patricia Scherschel, a Sallie Mae loan consolidation expert.