Ryanair's profits surged 66 per cent in the year to March as passenger numbers grew almost three times the targeted level on improved service and lower fares, with a more modest 10 per cent profit growth forecast for this financial year.

Passenger numbers increased 11 per cent to 90 million, compared with the four per cent targeted at the start of the year, with 100 million expected to fly with the Irish airline in the current fiscal year.

Europe's largest airline by passenger numbers said on Tuesday profit after tax hit €867 million and would reach between €940m and €970m this year.

Management said most of the growth was down to its Always Getting Better programme aimed at turning round its reputation for poor customer service.

Management credited the programme, which has brought in lower fees, flexible tickets for business travellers and a move away from small regional airports, for boosting average load factor - a key industry measure - by five per cent in the year to March.

"Always Getting Better is the key, it has been very well received," finance chief Neil Sorahan said.

Mr Sorahan said if expected "irrational fare cuts" by competitors don't materialise "maybe there is some upside" on the profit forecast, which chief executive Michael O'Leary described in a video presentation as "cautious."

Ryanair said its fares would be "broadly flat" in the six months to September. Its main rival easyJet has said revenue per seat would be down by about four percentage points in the three months to June.

Ryanair expects to increase passenger numbers by 10 per cent in the year to March 2016, with around half of this at primary airports and about half at smaller regional airports.

Forward bookings to September are on average four per cent ahead of last year, it said.

Ryanair again declined to comment on whether it planned to accept an offer by British Airways owner IAG for its 30 per cent stake in Aer Lingus.

The bid has stalled as IAG waits for the Irish government, which owns 25 per cent of Aer Lingus, to commit to selling. The government has said Ryanair's attitude was key to its decision.

"The Board of Ryanair will consider any offer from IAG on its merits, if or when it is received," Mr O'Leary said.