Airlines, which lost more than $9 billion last year, are asking Congress to rescue the industry by rewriting the federal law that governs airline labor relations to make it harder for unions to strike, according to officials representing major carriers.

The Air Transport Association, the industry's largest lobbying organization, is urging lawmakers to revise the Railway Labor Act of 1926, the federal law that regulates the industry's labor relations. Airlines, which have been struggling to regain profitability, say labor expenses are their biggest costs. If their employees' ability to strike is limited by the federal government, it could make it easier for carriers to win wage and work-rule concessions.

The effort is a shift in tactics for the industry, which failed last year in its effort to get Congress to pay for certain security costs and to eliminate some taxes. Lawmakers were reluctant to provide more funds for carriers after approving a $15 billion bailout for the industry after the terrorist hijackings in 2001.

Transportation unions said they were outraged by the effort and accused carriers of using their financial crisis to weaken unions. "It's about getting the upper hand on their workers," said Edward Wytkind, executive director of the Transportation Trades Department of the AFL-CIO, which represents 35 transportation unions, including all the airline unions. Airlines are one of the most unionized industries in the United States.

Last year Sen. John McCain (R-Ariz.) introduced a measure that would have changed the federal law by requiring that a panel of arbitrators quickly resolve disputes, effectively curtailing workers' ability to strike. Michael Wascom, a spokesman for the airline lobbyists, said the association and many carriers liked the measure, which did not pass.

With Republicans now in control of the Senate and McCain chairing the Senate Commerce, Science and Transportation Committee, airlines are hopeful that they can get the federal transportation labor law rewritten. McCain has scheduled a hearing Thursday on the state of the airline industry. His staff declined to comment on whether he would reintroduce the measure. But union spokesmen said they were told he would do so next month.

Not all airlines have endorsed this effort, according to industry and union sources. Some carriers, such as Delta Air Lines and American Airlines, are aggressively pushing for a new labor law, while a few, including Southwest Airlines, are unenthusiastic. "We're totally, incredibly uninvolved" in the lobbying effort, said Ed Stuart, a spokesman for Dallas-based Southwest. "Historically our negotiations have gone very well, and we're the most unionized airline in the industry."

The association's effort has been joined by a newly formed coalition of airlines, chambers of commerce, and state and local economic development and tourism agencies, which fear that airline cutbacks will hurt their communities. The group calls itself the Communities for Economic Strength Through Aviation, and its sole mission is to help airlines get more favorable labor rules. The group is headed by former New York representative Susan Molinari (R).

The airline industry's labor relations are governed by the 1926 Railway Act, which aimed to prevent railroad strikes that could hurt commerce and the national economy. When airlines began to grow as an industry, they were included under the measure. The law mandates a series of long cooling-off periods.

Some airlines say these cooling-off periods lead to lengthy negotiations that hurt the carriers. When threatened with strikes during this period, some airlines say they feel compelled to accept contracts that hurt them financially.

The legislation that McCain offered last year would eliminate the long cooling-off periods and require that labor disputes be referred to a small panel of arbitrators, which would have 30 days to select the proposal of the union or the company. The decision could be appealed only in limited cases and would be binding on both parties.

This process would require the arbitrators to consider the financial condition of the carrier and its need for a "reasonable profit." Molinari said this would help stop the common practice of labor unions forcing airlines to accept favorable contracts negotiated at other carriers.

"Compensation packages and wages have been excessive," said Wascom. "In times like this, you cannot sustain these levels of costs."

Molinari has recruited former transportation secretaries Neil Goldschmidt and James Burnley IV, former senators Slade Gorton and Charles S. Robb, and former representatives Vic Fazio and Vin Weber to lobby for the new group.

Wytkind said unions are upset that the airline industry is spending large sums to hire lobbyists while telling workers about their dire financial conditions. "It's become clear these 'broke' airlines who are pleading poverty and are trying to extract millions in concessions from their workers' wages have found the resources to hire a number of very high-profile lobbyists to lobby for this bill," he said.