All of the legacy carriers have said they are evaluating spinoffs. Furthest along is United, a unit of UAL ( UAUA ), which says it has identified a potential buyer for its maintenance operations and will brief union officials on the plan in the first quarter. Additionally, Northwest undefined has indicated it's looking favorably at the possibility of spinning off its frequent-flier program, while Delta ( DAL ) is studying whether to unload its regional carrier Comair.