Two major U.S. airlines are joining forces in a blockbuster partnership. United Airlines will team up with JetBlue in a new alliance they are calling "Blue Sky," the carriers announced Thursday.

United Airlines and JetBlue announced a new partnership Thursday that will allow passengers to earn and spend frequent flyer miles between the airlines. The arrangement, which the airlines are calling Blue Sky (no relation to the similarly named startup social media platform) will eventually allow each carrier's elite frequent flyers to receive reciprocal benefits and will bring with it other business perks for both companies.