NEW YORK (CNN/Money) - The chairman and CEO of the company that runs American Airlines said "groundbreaking accords" with three labor unions averted an immediate bankruptcy filing for the No. 1 airline, although he warned that the company's outlook remains uncertain.

Donald Carty, chairman and CEO of AMR Corp., said tentative deals with the pilots, flight attendants and transport workers reached Monday will help save $1.8 billion and keep the struggling company out of bankruptcy court for now. The last deal to be confirmed, with the all-important Allied Pilots Association, came late Monday evening.

Shares of AMR (AMR: Research, Estimates) gained 37 cents, or 18 percent, to $2.47 in pre-market trading on Instinet Tuesday following the after-market announcement of the final labor deal. That follows a gain of 52 cents, or 33 percent, in regular-hours trading Monday as reports of the progress towards labor deals circulated.

Still, despite the praise that Carty had for the deals, he warned in a statement that "the financial condition of American is weak and its prospects remain uncertain," adding that the war and the sluggish economy mean that " the days ahead will be difficult and the success of our joint efforts is not yet assured."

The pilots union, whose 13,500 American members account for the biggest share of the airline's labor costs, had made an offer Sunday that they said gave the airline the annual cost savings of $660 million it had been seeking.

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Earlier, the airline and the Transport Workers Union (TWU) said they reached a tentative agreement Monday covering about 16,000 mechanics. The statement from Carty put savings from that pact at $620 million.

Finally, Carty said the flight attendants union agreed to a plan that would save the airline $340 million. The latest word from the Association of Professional Flight Attendants negotiating committee was that the union's executive board hadn't yet passed that agreement.

Carty said that in a series of other concessions, the airline's agents, representatives and planners agreed to cut $80 million while management and support staff found ways to reduce costs by $100 million. That brought the total savings to $1.8 billion.

Carty announced some belt tightening of his own. The company said he will take a 33 percent pay cut, decline a bonus for the third straight year, and ask AMR's board to make further cut in the value his compensation package.

"By taking these decisive actions, the union leadership and our employees have demonstrated an unwavering commitment to the future of the company, and have enabled us to avoid an immediate filing with the bankruptcy court," Carty said. "The speed with which these comprehensive and complex agreements was reached is a testament to our people."

All of Monday's agreements still must be ratified by the unions' memberships. And the company still must secure what Carty called "meaningful concessions" from its vendors, lessors and suppliers.

The cost savings targets have not changed since the start of the war in Iraq almost two weeks ago, which sent airline bookings sharply lower. The troubles for the airline industry did not start with the war or even the Sept. 11 terrorist attack. American parent AMR Corp. has not reported a quarterly profit since the end of 2000, a full nine months before the attack.

The TWU Web site said the pact calls for a 17.5 percent pay cut for the mechanics as well as work rule changes worth about $139 million a year.

As for the pilots, the union said the next step is 14-day membership ratification process during which "all APA members in good standing will have the opportunity to vote for or against the Tentative Agreement," said a statement from the union, which did not release specific terms of the deal.

The airline still must slash $2.2 billion in non-labor costs from its annual budget. But since American had said it needed to have union agreements in hand by mid-April, and since the unions needed about two weeks to get rank-and-file ratification, Monday had been seen as a self-imposed deadline for American to get the tentative deals or move towards bankruptcy filing.

Industry analysts said the threat of bankruptcy at American may only be lessened, not eliminated, with the cost-cutting labor deals.

"I think it's still a possibility they may have to file for bankruptcy," said Jim Corridore, airline equity analyst for Standard & Poor's. "These agreements certainly help. It's good news for the company. But American has a lot of problems, and this only partly addresses the problems, especially given the sharp downturn in travel during the war."

American's largest competitor, UAL Corp. unit United Airlines, filed for bankruptcy protection in December, and US Airways Group, the nation's No. 7 air carrier, which filed for bankruptcy protection in August, was set to emerge from bankruptcy Monday after restructuring its labor and pension costs.

Airlines like American, United and US Airways, which operated a full network of hubs and flights structured to attract the business travelers who often pay full fare, have had trouble competing against low-fare competitors such as Southwest Airlines and Jet Blue, which operate more point-to-point operations.  

Reuters contributed to this report.