Ryanair has acknowledged that it might have to adjust its shareholding structure to comply with revised ownership rules once the UK formally separates from the European Union.
Some 40% of the Irish carrier is owned by US interests, says chief financial officer Neil Sorahan, and another 20% by UK shareholders.
While it currently complies with requirements that EU entities hold the majority of the carrier, the withdrawal of the UK from the EU potentially upsets this balance.
"It's something that may have to be dealt with," said Sorahan, speaking during a briefing in London on 6 April.
But he says he is confident that financial institutions will not have difficulty shifting quantities of shares to various holdings in order to ensure compliance.
Sorahan says, however, that the ownership issue is one of several areas of uncertainty for the airline regarding the UK's exit. There is still no clear indication about the ownership thresholds to be adopted following the withdrawal.
Ryanair is expecting to begin looking at measures such as UK air operator's certificate requirements within the next year, to prepare for a possible unfavourable outcome from UK-EU negotiations.
Sorahan is not reassured by the initial signals on the negotiations. "We need somebody to take control of the process," he says.
The best result would be continued membership of the 'open skies' partnership in which the UK currently participates with Europe. Sorahan says a failed negotiation and adoption of a World Trade Organisation structure would be the worst.
He stresses that, while there is no immediate threat to air traffic, there is a "distinct possibility" that flights between the UK and Europe would have to be suspended for a period after the negotiation deadline expires in March 2019 – adding that airlines have long seasonal lead times and will need to prepare ahead of this date.
"Someone has to point out the stark realities of what might happen," says Sorahan, adding that the issues need to be put "front and centre".