The Pentagon announced yesterday that it had found payroll records related to President Bush's time in the National Guard -- records that earlier this month were reported accidentally destroyed -- but the discovery did nothing to resolve the dispute over Bush's military service in 1972 and 1973.

The records cover the first quarter of 1969, when Bush served in the Texas Air National Guard, and the third quarter of 1972, by which time he had transferred to the Alabama National Guard to enable him to work on the U.S. Senate campaign of a family friend. It is Bush's claim of service in Alabama that has been challenged.

Bush moved to Alabama in May 1972, and his payroll sheet for July through September of that year shows no payment for those months, indicating no military service. But this lack of payment was apparent in pay records covering all of 1972 that the White House released in February along with a batch of Bush's other military files.

Defense officials yesterday attributed the earlier contention that the records had been destroyed to confusion over which boxes contained the relevant microfilm files at the Federal Records Center in Denver. The boxes are numbered, and the numbers are indexed in a binder, but government employees hunting for Bush's records last winter could not find the binder.

"Without it, they had to approximate the numbers and got them wrong," said Bryan Hubbard, a spokesman for the Defense Finance and Accounting Service. "When they couldn't locate the records, it was assumed they had been destroyed."

According to Pentagon officials, the payroll records of large numbers of service members were ruined in 1996 and 1997 in a project that attempted to salvage brittle microfilm reels.

In a search earlier this month to determine just how many records were lost, a DFAS employee came across the index binder, Hubbard said. This led to the boxes that contained Bush's missing records.

"We're talking about a 30-year-old manual process for managing records," Hubbard said. "That process has since been replaced."

White House officials have insisted Bush fulfilled his National Guard commitments, citing his honorable discharge in 1973. But some Democrats have accused him of shirking his duty.

Yesterday's announcement came days before Democrats are scheduled to begin a national convention in Boston to nominate Sen. John F. Kerry (Mass.) as their presidential candidate. Supporters of Kerry have sought to contrast his military service with Bush's. Kerry enlisted in the Navy, volunteered for combat in Vietnam and earned several medals for valor.

Pentagon spokesmen denied political considerations played a part in timing the disclosure that Bush's files had been discovered. Hubbard said the records were uncovered July 15.

Notification of the discovery came in letters to news organizations that had filed Freedom of Information Act requests for Bush's military records.

"The Department of Defense regrets this inadvertent oversight during the initial search efforts and the delay it caused in your receipt of these materials," said the letter, which was signed by C.Y. Talbott, chief of the Pentagon's Office of Freedom of Information and Security Review.