British Airways yesterday announced that chief executive Rod Eddington would leave the airline at the end of September.
Mr Eddington will be replaced by Willie Walsh, who until recently was chief executive of Aer Lingus.
BA chairman Martin Broughton said Mr Eddington had "performed miracles" at BA and had transformed the business beyond recognition.
The departure date of Mr Eddington has been the subject of frequent speculation, with reports suggesting the airline boss wanted to be back in his native Australia by January.
Since taking the helm, Mr Eddington has endured some testing times, following the Concorde disaster, the post-September 11 travel slump and the Sars epidemic.
He has also overhauled the route network, changed working practices and brought 13,000 job cuts as part of a Future Size and Shape strategy.
Mr Walsh, who is 43, carried out a similar exercise at Aer Lingus after taking over as chief executive in the wake of September 11.
Mr Broughton said Mr Walsh's success in leading Aer Lingus back to profitability meant he was the best person for the job.
Mr Eddington, who is 55, has already told the City that the BA job would be his last in the aviation industry. He is said to be planning to concentrate on his nonexecutive posts, which include a senior role at media group News Corporation.