United CEO Scott Kirby and American CEO Robert Isom were once colleagues known as the ‘dream team.’ Now Kirby wants to acquire his rival

One takeover attempt is bold. Two? Rare indeed. But when news broke in mid-April that the United CEO was interested in acquiring his rival American Airlines, it was the third time this maverick air exec decided he wanted to reshape the playing field. As Fortune reported earlier, it’s far from clear such a merger would ever be approved, and on Friday American said it was “not engaged with or interested in any discussions regarding a merger with United Airlines.” Still, sources that spoke to Fortune...