The U.S. Department of Justice said on Wednesday it is investigating whether U.S. airlines worked together illegally to keep airfares high by signaling plans to limit flights.
The Justice Department wrote to major U.S. air carriers demanding that they detail decisions to limit the number of seats they offer, and what they've said about those plans to investors, securities analysts and the public.
Airlines contacted have been asked to provide "available seat miles on a regional and system wide basis" back to January 2010, along with a raft of other data.