Passengers will see favorable -- and not-so-favorable -- changes if the deal is approved. By Cameron Huddleston, Former Online Editor May 3, 2010 United Airlines and Continental Airlines announced today that they're merging to create the world's biggest airline. The deal must win antitrust approval before it can be finalized, but here's what travelers likely can expect: Fares likely will rise in the short term -- especially on the 13 routes flown between the two airlines' hubs (such as Newark to Los Angeles), says Airfarewatchdog.com president George Hobica. Other airlines likely will follow with rate hikes of their own. Booking travel on United and Continental today or in the near future will not be affected, according to United. You can continue to make reservations with either United or Continental. You can continue to use frequent-flyer miles from both of the airlines' programs, according to United. Once the merger is complete, your miles will be combined into one account if you have them from both programs. Advertisement If the merger is approved, United's higher fees likely will be adopted on routes flown by Continental, says Hobica. See SmartTravel.com's Airline Fees: The Ultimate Guide to compare the two airlines' fees. United's Economy Plus seating, which provides extra leg room for additional fees, likely will be extended to Continental flights, Hobica says.