Oneworld will hold an event announcing a "significant membership development" on 8 October, coming amidst widely-reported discussions with Qatar Airways about joining the alliance.
The event will be held in New York and includes Bruce Ashby, chief executive of Oneworld, Tom Horton, chairman and chief executive of American Airlines, and Willie Walsh, chief executive of International Airlines Group (IAG), according to documents obtained by Flightglobal.
Qatar has been linked to joining one of the big three alliances in the near future.
Snagging the Doha-based carrier would be a coup for Oneworld. It would be the first of the big three alliances to include one of the major Gulf airlines and would ratchet up pressure on SkyTeam and Star to forge partnerships with either Emirates or Etihad.
Oneworld already includes Royal Jordanian as a member and SriLankan Airlines is slated to become a member in late 2013.
Qatar declines to comment on whether it is joining Oneworld.