WASHINGTON – Comair and its striking pilots reached a tentative contract agreement Thursday to end a 21/2-month walkout that has shut down the nation’s second-largest regional carrier.

The deal between Comair and the Comair chapter of the Air Line Pilots Association came after three days of talks with federal mediators.

“Our negotiating committee and elected leaders endorse this agreement, recommending that our members adopt it because we believe it satisfies the pilots’ fundamental requirements,” J.C. Lawson, union chairman, said in a joint statement with Comair.

“This is good news for our customers, the communities we serve and our employees,” Randy Rademacher, Comair’s president, said in the statement. “We saw this latest negotiating session as an opportunity to bridge the remaining gap between the company and its pilots, and we’re very pleased to have arrived at terms that the union representatives could embrace.”

Details of the proposal were not immediately available.

“We’re going to let the statement speak for itself,” Comair spokeswoman Meghan Glynn said. Union officials did not immediately return telephone messages Thursday.

A source close to the negotiations between Comair and the pilots said Thursday the union has agreed to speed the ratification process to conduct a vote on the agreement within 10 days.

“I certainly hope they will accept it,” said Rebecca Hupp, interim director of Bangor International Airport.

Comair, based at the Cincinnati/Northern Kentucky International Airport and owned by Delta Air Lines, has been shut down since the strike began March 26. Comair flew three round-trip flights a day from Bangor to Cincinnati before the strike. Last summer, it flew four round-trip flights. Because of the continuing strike, however, flights were canceled through the end of July.

In Bangor on Tuesday, Delta announced that another carrier, Atlantic Coast Airlines of Virginia, would begin five round-trip flights from BIA to Boston starting Aug. 1. The addition of ACA as a Delta Connection at the Bangor airport, however, was not being viewed as a replacement for Comair, according to local officials.

“Based on our conversations with Delta we fully expect that Comair service will return to Bangor,” Hupp said Thursday. But even if the agreement is approved soon, Hupp didn’t expect Comair would be able to begin flights again until after July.

As part of ACA’s expansion to Bangor, Delta hired 19 of the 20 people who worked at Comair’s operations in Bangor to handle its ACA traffic. All but four of the 20 Comair staffers were laid off May 23 because of the strike. The one person who was not rehired has moved from the area.

Officials said that when Comair returns, the workers will handle both operations.

In discussing the upcoming vote by pilots, Lawson, the union chairman, said in a statement that informational meetings are planned, followed by telephone balloting. Thursday’s agreement “differs substantially from the other settlement proposals on which they’ve voted previously,” he said.

Pilots overwhelmingly rejected an initial proposal offered by the mediation board on May 12. They said it did not meet their demands for salaries more in line with larger carriers, shorter shifts, a company-paid retirement program and longer rest intervals between shifts.

Comair and union officials also have started creating teams that will help smooth the process of restarting operations, including addressing management-employee relations caused by the 81-day strike.

“We’re eager to redirect all of our energies toward our customers, and rebuilding our relationship with them,” Rademacher said in the statement.

Comair officials will announce plans to resume airline operations after the pilots vote on the proposed contract.

The tentative agreement follows a meeting last week with Transportation Secretary Norman Y. Mineta, who urged the parties to resume talks and try to reach a settlement by Thursday. They have been negotiating since 1998.

The agreement “demonstrated that with the proper commitment on both sides, even thorny issues can be resolved at the bargaining table,” Mineta said.

Other major labor disputes remain, including American Airlines flight attendants, who plan to strike at the end of the month unless President Bush intervenes.

“My message to those parties is the same one we discussed with Comair parties in my office last week – let’s make the system work for everyone, especially the traveling public and business,” Mineta said.