Two of the three largest airlines in the world will be led by Irish executives from September, following the appointment of Willie Walsh as chief executive of British Airways.
Based on the latest market valuations, Mr Walsh will be taking the helm of the third-largest airline in the world, valued at $5.8 billion (or €4.3 billion). He has pledged to continue the work of current chief executive Rod Eddington, who is expected to return to Australia. The post of BA chief executive commands an annual salary of €804,000, plus share options.
Ryanair chief executive Michael O'Leary is already running the second-largest airline in the world, based on a market valuation of $6.7 billion. The low-cost US carrier, South West Airlines, is the most valuable carrier.
Mr O'Leary commented: "Aer Lingus's loss is BA's gain."
This remark was echoed by Fine Gael, which said Aer Lingus had suffered a huge blow with Mr Walsh's departure. Transport spokeswoman Olivia Mitchell said Aer Lingus had lost Mr Walsh to a major rival.
"When the open-skies policy comes through, the airlines will be competing for the profitable US routes," she said.
The Department of Transport said the process to select a replacement for Mr Walsh was continuing. The Government is also consulting the social partners and other stakeholders about the airline's future.
The two senior executives who left Aer Lingus earlier this year along with Mr Walsh are in talks with several airlines about future opportunties.
They have not ruled out setting up their own airline, but the appointment of Mr Walsh to the British Airways post appears to make this less likely.