Colorado's largest airline is being required to slash annual labor costs by $2.4 billion.
Lenders that are enabling United Airlines to keep flying during bankruptcy are demanding United make the cuts in two months.
The total would more than double the approximately $1 billion in yearly concessions unions agreed to this fall as part of a failed bid to keep the airline out of bankruptcy.
Airline officials aren't commenting. The Association of Flight Attendants told its members that United management last week informed union negotiators that the restructuring plan calls for the cuts.
Mechanics, who earlier rejected a 7% pay cut, are now being asked to take a 13% cut.