The merged American Airlines - US Airways would be the world 's largest airline . Lawsuit : The merger would ` ` substantially lessen competition '' for air travel . Previous mergers won approval in recent years amid the poor economy , but it now loses money . NEW : American / US Airways say they will fight government attempt to block their deal .
The merged American Airlines-US Airways would be the world 's largest airline . Lawsuit : The merger would `` substantially lessen competition '' for air travel . Airline mergers won approval in recent years amid the poor economy , but industry now making money . NEW : American/US Airways say they will fight government attempt to block their deal .