Willie Walsh has taken over as chairman of the oneworld alliance.
The IAG chief takes over from American Airlines chairman Tom Horton, who has filled the role since December 2011.
Oneworld CEO Bruce Ashby thanked Horton for his leadership "during a period of unprecedented growth for the alliance and at a time when his own American Airlines has been undergoing its merger with US Airways".
"We are fortunate to have, in Willie Walsh, a man with the vision, determination and overall skills and capabilities to lead us forward in the next phase of our journey to establish oneworld firmly as the first choice alliance for frequent international travellers the world over," he added.
At the end of this month, the alliance will be joined by TAM Airlines and US Airways, while SriLankan Airlines will join on May 1.
