On Monday, US Airways officially joined Oneworld, the alliance founded by American Airlines.
The carrier formely left United Airlines' Star alliance on Sunday and had stopped selling tickets on Star alliance carriers' earlier this year. With its merger with American, US Airways had been transitioning its rewards programs to American and Oneworld.
Oneworld also welcomed TAM Airlines to its alliance. The Brazilian airline also joins the group via a merger. Its merger partner, LAN Airlines, has been a Oneworld member since 2000.
The alliance said that US Airways Dividend Miles Platinum and Gold Preferred members now have Oneworld Sapphire status which entitles them to use Business Class or frequent flyer lounges of any oneworld alliance partner and can check-in at Business Class desks whenever they depart on a oneworld alliance partner flight, regardless of their ticket.