NEW YORK (CNN/Money) - Union and management negotiators at American Airlines have reached agreement on a framework to keep the company out of bankruptcy, but both sides need to win approval from their respective boards, according to union spokesman and a congressman who brought the two sides together.

Rep. Martin Frost, D-Texas, and John Richards, spokesman for the Transport Workers Union, both said Thursday that the agreement was reached late Wednesday night after more than 12 hours of meetings between the presidents of the three major unions at the airline and top management of American. Neither man knew any of the details of the deal. Frost left Wednesday's meeting after a few hours but he said representatives of both sides told him of the agreement.

"The only thing we know is the company is trying do anything to try to salvage this deal to stay out of bankruptcy," said Richards. He said union leadership had set a conference call to discuss the new agreement to save the concession pacts starting at 3:30 p.m. CT.

Frost said it is not at all clear that the union presidents can win the approval of their boards of directors for the deals. And he said the board of directors of American Airlines parent AMR Corp. (AMR: Research, Estimates), which is meeting Thursday in Dallas, also is weighing a possible bankruptcy filing as well as the agreement that was worked out.

Union and management negotiators at American Airlines have reached a deal after twelve hours of talks. CNNfn's Greg Clarkin reports from Fort Worth, Texas, on the agreement. Play video (QuickTime, Real or Windows Media)

"Management conveyed that if they didn't have certainty that things are settled with the unions, they will be looking at bankruptcy," Frost said.

Spokespeople for American Airlines were not immediately available for comment on Frost's statement. George Price, spokesman for the Association of Professional Flight Attendants, and David Dominy of Allied Pilots Association had no comment on Frost's statement. The pilots' Web site did say its board of directors is meeting Thursday.

The three unions ratified concession labor pacts last week that would save the airline $1.6 billion a year over the next six years, which were central to the company's efforts to cut labor costs by $1.8 billion annually and return to profitability.

But when the unions found out that management had approved retention bonuses and pension guarantees for the airline's top executives, they threatened to pull out of the labor deals. Management dropped the retention bonus plan Friday, but the APFA and the TWU have said they will poll their members again on the contracts, causing a delay that could force the world's largest airline to file for bankruptcy protection. The concessions had been due to take effect May 1.

Wednesday's meetings took place the same day AMR announced a first quarter loss of $1.05 billion, which was almost twice the year-earlier loss and larger than analysts' consensus forecast.

Frost said the possibility of AMR Corp. Chairman Don Carty resigning due to union outcry was brought up at the meeting, but that Carty's departure was "never laid out as a requirement for deals."

A spokesman for University of Oklahoma President David Boren, a member of the AMR board, told CNNfn that Boren would be introducing a resolution at Thursday's board meeting calling for Carty's removal.

"In my opinion, Mr. Carty has lost the credibility and trust necessary to effectively lead the company through challenging times," said a statement confirmed by Boren's office. "Most members of the board had been led to believe that Mr. Carty had fully disclosed the executive retention plan to labor leaders. I was personally shocked when I read in the newspaper that he had not done so."

Boren, a former Oklahoma governor and senator, said he believes Carty did not even inform some senior members of management that the unions had not been informed of the executive compensation deals.

"We have some of the greatest employees in the world at American Airlines," said Boren's statement. "I hope that even at this late hour labor, management and new leadership will be able to get together on an agreement to save the company and as many jobs as possible."

Rep. Martin Frost

Frost said that while there is a lot of union hostility to Carty, he believes he can still work with the unions.

"Prior to these recent disclosures, Carty had a good relationship with these unions," Frost said. "The mood [at Wednesday's meeting] was constructive. They all wanted to avoid bankruptcy. The question is if the company could now put something else on table that would lessen the ill will and stop the unions from holding new ratification votes." Frost said that one thing the unions wanted to explore Wednesday was not having the contracts last six years.

The Wall Street Journal reported Thursday that the AMR board is deeply split between chief executives and former chief executives who want to back Carty and who are ready to file for bankruptcy if the unions don't drop their threats to revote the labor deals, and those who are ready to remove Carty if it would keep the company out of bankruptcy.

Carty does have close ties with several of AMR's outside directors. For example, he and board member Michael Miles, the chairman of the board's executive compensation committee, serve together on two other boards -- Dell Computers Corp. (DELL: Research, Estimates) and Sears Roebuck & Co. (S: Research, Estimates) Another AMR board member is Edward Brennan, the retired CEO and chairman of Sears, where Carty has been a director since 2001.

One union official at American, who spoke to CNN/Money on condition his name not be used, said earlier this week that the unions have been reluctant to formally call for Carty's resignation despite rank-and-file outcry against him due to the belief of leadership that Carty has been a strong advocate of staying out of bankruptcy.

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"The board has said, 'Go ahead and file.' Carty is one who has pushed board not to file bankruptcy," said the union official.

The Wednesday meeting included Frost and three Republican congressmen from Texas, home of AMR Corp., as well as the unions. Frost said that he and the congressmen were acting as facilitators, not mediators.

"I have a good relationship with both sides. I tried to play the role of honest broker, get the sides together to talk," Frost said. "We at least were able to do that. We'll have to see how it turns out."

Frost said the future of American will probably be known Thursday. "I think there will be a resolution one way or another today," he said.

Shares of AMR (AMR: up $0.23 to $4.03, Research, Estimates) were about 7 percent higher in trading Thursday.