Mr Willie Walsh, Chief Executive of International Airlines Group (IAG), owner of British Airways, has announced he is to step down from the board on 30 June.
Walsh said it had been a privilege to have worked on the creation of IAG after British Airways (BA) and Iberia were merged.
Mr Antonio Vázquez, IAG’s chairman, described Walsh as one of the “main drivers” of the project.
Walsh became the British Airways boss in 2005 and is ending a 15-year career with the IAG group, which also controls Aer Lingus and Vueling.
He is expected to step down from the role in March before retiring in June this year.
Walsh said: “It has been a privilege to have been instrumental in the creation and development of IAG.
“I have had the pleasure of working with many exceptional people over the past 15 years at British Airways and at IAG.”
Willie Walsh is a long-standing figure in the aviation industry. He joined Aer Lingus in the late 1970s as a cadet pilot.
He gradually worked his way up through the ranks to work in flight operations and was appointed as chief executive of Aer Lingus in 2001.
Mr Luis Gallego, head of the group’s Spanish division, Iberia, since 2014, is expected to succeed Walsh.
He said: “It is a huge honour to lead this great company. It is an exciting time at IAG and I am confident that we can build on the strong foundations created by Willie.”
Gallego will take over as head of the holding company of British Airways after the airline saw major disruption last year.
For the first time in its 100-year history, BA pilots went on strike in a long-running pay dispute.
In November, dozens of British Airways flights were also delayed or cancelled because of a “technical issue”. The airline also faced a £183m fine in July for a customer data breach.
The UK’s flag carrier also dropped to 55% for customer satisfaction for both short and long-haul flights in a recent survey by consumer group Which. This was well below easyJet and several other budget airlines.