Irish low-cost airline Ryanair logged rebounding quarterly profits on Monday, aided by the timing of Easter, but added that the outlook remains clouded by Brexit.

Earnings before tax, or net profit, rallied 55 percent to 397 million euros ($463 million) in the three months to June 30 from a year earlier, Ryanair said in a results statement.

The performance was boosted by the timing of the Easter holiday.

Easter -- a peak-time for holidaymakers -- fell in April this year, inside Ryanair's reporting period. In 2016, it fell in March.

"We are pleased to report this 55-percent increase in profit after tax ... but caution that the outcome is distorted by the absence of Easter in the prior year first-quarter," said Chief Executive Michael O'Leary.

The Easter boost was partly offset by a Brexit-fuelled slump in the pound -- which reduces the amount Ryanair earns from its key British market once the currency is converted into euros.

The Dublin-based carrier warned once again of the impact of Britain's looming exit from the European Union, set for March 2019.

The group has repeatedly forecast major disruption if Britain does not remain in the "Open Skies" agreement following its departure from the bloc.

Last Friday, Ryanair's chief commercial officer David O'Brien warned that the airline will slash flights between Britain and the EU if London and Brussels fail to agree on terms for post-Brexit air travel by September 2018.

"We remain concerned at the uncertainty which surrounds the terms of the UK's departure from the EU in March 2019," Ryanair added on Monday.

"While we continue to campaign for the UK to remain in the EU Open Skies agreement, we caution that should the UK leave, there may not be sufficient time, or goodwill on both sides, to negotiate a timely replacement bilateral which could result in a disruption of flights between the UK and Europe for a period of time from April 2019 onwards.

"We, like all airlines, seek clarity on this issue before we publish our summer 2019 schedule in the second quarter of 2018.

"If we do not have certainty about the legal basis for the operation of flights between the UK and the EU by autumn 2018, we may be forced to cancel flights and move some, or all, of our UK based aircraft to Continental Europe from April 2019 onwards."

Ryanair's fierce British rival EasyJet announced last week that it has secured an air operator's certificate in Austria to enable it to keep flying across the EU following Brexit.

Britain's airline industry has soared over the past two decades under the Single European Sky system, which lifted trade restrictions on EU airlines.

Unless British negotiators manage to secure preferential conditions, airlines could lose this status once the country leaves the EU.

source: AFP