The Federal Aviation Administration is proposing rules this week to strengthen regulations on emergency exit doors on commercial jetliners.

The proposed rule change is the latest move in a long-smoldering dispute between the FAA and the Boeing Co. over Boeing's proposal to reduce the number of emergency exit doors on the main cabin level of its 747s from 10 to eight.

The new rules will require that passengers not be seated more than 30 feet from the nearest exit door, and that adjacent doors be separated by not more than 60 feet.

Anthony J. Broderick, associate administrator for aviation standards, said the present rules, written during the 1960s when planes were smaller, need to be updated to reflect the era of wide-body jumbo jets.

"The rules, as we wrote them in 1966, have loopholes," Broderick said. "Planes were smaller then, and the big planes conceived at the time had plenty of doors."

But underlying the change is a four-year old dispute with Boeing that suddenly heated up in September when Boeing filed suit in the 9th Circuit Court of Appeals in San Francisco challenging the FAA's contention that the Seattle-based manufacturer cannot reduce the number of exits.

Present FAA regulations require there must be two emergency exit doors for every 110 seats and that a manufacturer be able to show that a fully-loaded aircraft can be evacuated in the dark within 90 seconds, with half the doors inoperable.

The 747, with five pairs of doors, has enough emergency exits for 550 passengers. But most of the 747s seat between 350 and 440 passengers. Boeing points out that it can reduce the number of doors, add seats and still meet FAA requirements.

When Boeing first asked the FAA, in 1983, to allow it to eliminate its exits over the wings, the agency's Seattle aircraft certification office said yes. When the proposal reached headquarters here, then-FAA chief Donald D. Engen said no.

By removing the doors, there would be 72 feet between the next closest exit doors -- a distance the FAA says is too great to maintain a proper margin of safety.

Last July, the FAA wrote Boeing a letter, explaining that the agency would not certify the new 747-400 model if its over-wing doors were eliminated.

Elizabeth Reese, a Boeing spokeswoman, said the manufacturer intends to continue making the aircraft with five pairs of doors. "We can build our airplane. They come out with ten holes punched in them," she said.

Boeing, irked at what it considers a flip-flop in FAA policy, contends that it sued the government "on procedural grounds" to protect its right to challenge government regulations.

"The only thing the suit is doing is challenging procedure," Reese said. "They made a change and didn't go through the normal process."

But the Association of Flight Attendants, which represents 23,000 flight attendants working for 12 airlines, said an issue involving air safety should not be argued on procedure.

Our view is that it's a terrible thing when a company sues the FAA to cut back on safety," said Matthew Finucane, spokesman for the flight attendants. "The FAA has the authority, we believe, to prohibit unsafe practices, regardless of whether a regulation specifically prohibits it."

Reese said Boeing would have no further comment on the proposed changes until company executives have had a chance to review them.