Airline passengers paid the federal government nearly $1 billion for security last year, more than six times the amount the airline industry paid, according to the agency in charge of airport security.

Both passengers and airlines were required by Congress after the terrorist attacks in 2001 to help pay for security. But passengers have paid far more and airlines far less than the government first predicted.

Passengers paid $977 million in the fiscal year that ended in September, through $2.50 security fees that have been added to airline ticket prices for each segment of a flight since last January, the Transportation Security Administration said.

During the same period, airlines paid $160 million, although the industry did not begin making payments until midway through the fiscal year. This fiscal year, the TSA expects airlines to pay $318 million for security, according to congressional and industry sources.

"The airlines are not paying their fair share," said Rep. James L. Oberstar (Minn.), the ranking Democrat on the House Transportation and Infrastructure Committee. "They're wringing their hands, whining that they have all this financial burden, and yet travelers are paying five or six times what the airlines are paying. Air travelers have agreed to pay that money, and I never hear a complaint from anybody."

Exactly how much the carriers are supposed to pay has been debated by the airline industry and the Transportation Department for several months.

Transportation Department Inspector General Kenneth M. Mead has insisted that the airlines owed $750 million, while the industry's largest lobbying group, the Air Transport Association, has said that they will pay only $300 million.

TSA spokesman Robert Johnson said, "We're the designated agency handling the proceeds, but otherwise we'll leave this to Congress to determine the best direction."

The issue may be resolved during this legislative session, said Michael Wascom, a spokesman for the Air Transport Association.

"We're optimistic that as a new Congress convenes and as a variety of challenges continue to face the industry, that this particular issue can be resolved in an amicable fashion," Wascom said. "There are a variety of other pressing issues that command our attention, such as rising fuel prices and excessive taxation. We don't want to be distracted" by this issue.

Airlines, which received $5 billion in cash assistance from Congress after the terrorist hijackings, balked at paying the $750 million sought by Transportation because they said they have not been reimbursed for up to $4 billion in other security costs, including the expense of reinforcing cockpit doors, placing air marshals on planes and complying with new restrictions on carrying mail.

Airline executives, who failed to win financial relief from these costs last year, said they still plan to press for a "rollback" of security expenses. They also hope to have the $2.50 fee eliminated because they say it prevents them from raising prices.

Airline executives from American, Northwest and US Airways are scheduled to testify today before the Senate Commerce, Science and Transportation Committee about the state of the industry, which lost an estimated $9.5 billion last year.