Report: US Airways CEO asked Delta about merger

US Airways CEO wanted to merge with Delta Airways after Delta filed for bankruptcy. Delta decided not to merge with US because they have decided to exit bankruptcy court next spring and become a stand alone company again. If this would have went through Delta could have possibly started to have some price discrimination because they could have more of the routes in the United States after they merged. Delta could have also started merging with more and more airlines until the government would have to step in and break Delta up into multiple companies, just like they have done to other monopolies in the past. How big would Delta have to get before they broke them up?