Aer Lingus has confirmed that chief executive Dermot Mannion is stepping down from his post, effective immediately.
Chairman Colm Barrington is taking responsibility for the airline until a new chief has been appointed.
Aer Lingus' board has accepted Mannion's decision but it has not given any reason for his decision.
Mannion, who was appointed four years ago, says his departure will "allow a new chief executive to bring fresh thinking and new ideas to the business".
Aer Lingus recently turned in heavy losses and is still facing a financial struggle. Mannion has resisted two takeover attempts by Irish budget carrier Ryanair.
Efforts to underpin the airline's independence, through expansion into non-Irish bases, and measures to cut costs also generated friction with unions during his term.
While Aer Lingus dropped its alliance membership by pulling out of Oneworld it has formed partnerships with US carriers United Airlines and JetBlue Airways.
Acting chief Barrington says: "Against the backdrop of challenging market conditions, the board and management team are focused on maximising revenues, reducing operating costs while maintaining a strong balance sheet to deliver value for all shareholders."
Source: Air Transport Intelligence news
