The Federal Aviation Administration, citing concern over the experience levels of the pilots in the crash of a Continental Airlines jet at Denver's Stapleton Airport, yesterday asked airlines to avoid assigning inexperienced pilots to the same flight.

The agency also announced it is tightening rules regarding aircraft maintenance and released statistics showing a huge increase last year in the number of near-collisions.

In an advisory to major U.S. airlines, the FAA recommended that in bad weather, captains make all takeoffs and landings when teamed with a copilot who has fewer than 100 hours of experience in that aircraft type.

The move marks the first time that the FAA has attempted to place a value on pilot experience as a means of measuring safety. And the change comes midway through the agency's first review of pilot-qualification standards in 30 years.

"We're not prejudging with respect to the Denver tragedy," said FAA chief T. Allan McArtor, emphasizing that there is no indication the experience levels of the pilots had anything to do with the crash.

Despite their overall experience, the pilot and copilot of Continental Flight 1713 had relatively little flying time in the DC9-10 model that crashed Nov. 15 while taking off from Denver in a snowstorm. Lee Bruecher, who was making his second flight as a DC9 copilot, was flying the jet when it got into trouble and flipped onto its back, killing 28 of the 82 people on board.

"We're not suggesting an inexperienced pilot is not qualified," McArtor said. But he said experienced adds "familarity, confidence and proficiency" to the pilot's repertoire. "It's not that you don't have this, you increase this," he said.

Throughout the industry, pilots who pass the qualifying exams are considered qualified to fly. Pairing inexperienced pilots, particularly at expanding airlines, is an industry-wide practice.

"If they're saying his training isn't adequate to allow him to fly with any of the other pilots on that airline, then we say the training program is inadequate," said Henry A. Duffy, president of the Air Line Pilots Association, which represents 39,000 airline pilots.

Duffy, however, praised the FAA for pushing the airlines to repair equipment on aircraft more promptly. The FAA directed airlines to reduce the number of deferred maintenance items in a more timely fashion and set new deadlines, ranging from 24 hours to 10 days.

Aircraft are built with redundant systems, which are designed to get the aircraft home safely in case something goes wrong. Largely as a result of these redundancies, the FAA rules allow aircraft to continue operating with certain items malfunctioning until the plane passes through an airport where the repairs can be made conveniently.

More recently, the policy of allowing deferred maintenance has been abused, and some aircraft are operated long after repairs could have been made.

"There was some gamesmanship with minimum equipment lists," McArtor said. "Well, that's over."

Delays to maintenance were brought to light in congressional hearings last fall when pilots for Eastern Air Lines accused their employer of deferring maintenance to such an extent that it was placing its passengers at risk by pressuring pilots to fly planes in need of repairs.

McArtor said the problem with deferred maintenance was "certainly illuminated" by the Eastern incidents. But he said the changes were prompted by a survey of 11 airlines.

"This is an industry-wide problem, with respect to the minimum equipment list," McArtor added.

Statistics compiled by the airline pilots' group show that between January and October of last year, Eastern's monthly maintenance reports contained 350 to 400 unrepaired items for its fleet of 279 planes.

By comparison, Delta Air Lines's monthly reports, for a fleet of a similar size, contained 35 to 40 unrepaired items. U.S. Air, which operates a fleet half the size of Eastern, compiles monthly reports containing about 20 unrepaired items.

The FAA released year-end statistics showing a 26 percent rise in reports of near-collisions over 1986. Pilots reported 1,056 near-collisions last year, compared to 840 in 1986. Of about 900 investigated, 18 percent were listed as "critical," meaning aircraft passed within 100 feet or less of each other.