NEW YORK (CNN/Money) - American Airlines' pilots union expects that the world's biggest airline will file for bankruptcy this week if it does not reach tentative new labor agreements by Monday.

"I don't believe that American believes there's any reason to wait in absence of agreements," Gregg Overman, spokesman for the Allied Pilots Association, told CNN/Money Friday.

"Management indicated they needed to have agreements no later than the middle of next month. We and the other unions have to have ratification by rank and file for which we need about 14 days. So the Monday is somewhat of a mutual deadline."

Airline spokesman Todd Burke said the airline has not given any specific deadline for when labor deals must be reached or a possible bankruptcy filing would occur. He also wouldn't speculate on the timing of a possible filing.

"We've not set a deadline. All I can say is (American CEO Donald) Carty has said time and again the losses are not sustainable," said Burke. "We remain focused on doing everything we can to avoid bankruptcy."

Unlike United Airlines, which filed for bankruptcy protection in December, American has not missed any debt payments. But airlines generally prefer not to nearly run out of cash before filing for protection from creditors.

"American has expressed views that United should have gone into bankruptcy with more cash available," said Overman.

Airlines can and generally do keep flying immediately after filing under Chapter 11 of federal bankruptcy law, which gives companies protections from creditors while they reorganize and shed debts. Bankruptcy courts also have the power to void labor contracts seen as too costly.

Management and the unions at the world's No. 1 airline are therefore expected to hold intensive talks Friday and over the weekend to reach new deals. And the unions say they are getting close to coming up with the $1.8 billion in annual savings being demanded by the airline.

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Overman said the pilots remain confident a deal that saves American the $660 million it is looking for in labor savings from the pilots can be presented to union leadership for consideration by Monday. "That's a 'no-later-than' date. It could be sooner than that," he said.

The pilots union, representing 13,500 employees, said Sunday it had offered a package of concessions worth that amount, mainly from work rule changes and across-the-board pay cuts, Reuters news agency reported.

The flight attendants union, representing 26,000 workers at American, said Friday it had offered a deal to meet its target of $340 million in annual savings.

"We appreciate the spirit of cooperation and collaboration this action symbolizes," American's Burke said of the flight attendants' offer. "We are now in process of jointly costing out the proposal to determine whether it meets the cost targets established."

The Transport Workers Union reached a tentative agreement Thursday for its 16,000 members who work at American as baggage handlers and in related jobs. The union said Saturday it had reached tentative deals for five of its eight working groups, representing another 2,300 workers, but that it was still negotiating for another roughly 16,000 mechanics at the airline, according to Reuters. American is seeking $620 million in savings from TWU.

The unions are weighing possibly taking an ownership stake in American parent AMR Corp. as part of any concession deals. Shares of AMR Corp. (AMR: down $0.21 to $1.58, Research, Estimates) fell further Friday on concerns about the possibility of a bankruptcy filing.

The company has not given any details about the drop in bookings since the start of fighting with Iraq, other than to say it has not seen a spike in cancellations of already booked flights. But the decline in bookings has been sharper than anticipated, said George Price, spokesman for the Association of Professional Flight Attendants (APFA), which represents the 26,000 flight attendants at American.

"We're basing our negotiation on what the company is providing us," said Price. "We're continually monitoring the books and their bookings."

Price and American spokesman Todd Burke both said that American management has not raised its labor cost-cutting target since the start of the war. Nor have new layoffs been announced, though more than 600 flight attendants and about 1,000 pilots have been targeted for furloughs unrelated to the drop in bookings.

The airline has also announced an additional 6 percent cut in its international flight capacity to take effect in April, due to the war-related drop in bookings.

In addition to labor talks, AMR is also reportedly in negotiations with lenders about lining up $1.5 billion in loans that would be used during a bankruptcy reorganization, so-called "debtor in possession" financing. Reuters reported Thursday that the talks on DIP financing were getting close to conclusion and that a bankruptcy filing could come as soon as next week.

APFA's Price also said that the union has not been given any specific deadline for a bankruptcy filing by management in the current round of talks.

"We have not be notified of an imminent bankruptcy filing," Price said. "I would hope they would notify us if something was going to be filed. As far as those reports, I certainly think the company is trying to get plan B put together just in case."

The TWU deal for baggage handlers is contingent on "negotiation of an acceptable equity stake in the company on behalf of all TWU members," said a statement on the union's Web site.

The pilots union's board of directors had a presentation made to it on a possible employee stock ownership plan for American by a group of pilots from the Los Angeles area, Overman said. Overman said that such an equity stake is possible as part of a deal to avoid bankruptcy, or as a part of a bankruptcy reorganization.

A number of airline labor groups have seen their members take a stake in their airlines, particularly in return for concessions. But those agreements have problems as well.

United Airlines parent UAL Corp. was majority owned by its employees, but that was not enough to stop it from filing for bankruptcy in December. The employee stock ownership plan (ESOP) sold its controlling stake in the company as shares plunged, and most of the employees' holdings were virtually wiped out.

The union influence at UAL under the ESOP is blamed by some for the airlines' problems. Some airline and ESOP experts said that the structure of the UAL stock plan, which exchanged shares for concessions, doomed the ESOP to failure.

Overman said the problems at United will make APA cautious about any stock ownership plan at United, but not stop the union from pursuing the idea.

"You can look at it another way, we can learn from their mistake," he said. "Particularly if the airline ends up in bankruptcy, we have to look at a variety of alternatives."  

Reuters contributed to this report.