Budget airline Ryanair has boosted profits in the first three months of its year and said it expected fares to fall in the winter as it adds new routes and bases.

The Irish no-frills carrier, which is celebrating its 30th anniversary, said lower oil prices and industry-wide discounting would lead winter fares to be at the upper end of its minus four per cent to minus eight per cent guidance.

Chief executive Michael O'Leary said the airline would expand by 15 per cent in the winter compared with last year as it opens routes, adding he expected rivals to react by "putting downward pressure on fares".

The airline said its profit jumped 25 per cent to €245 million (£175 million), in the first quarter of the year to the end of June, compared with 12 months ago, as passenger numbers leapt 16 per cent to 28 million in the period.

Mr O'Leary said the carrier enjoyed a "very good" first three months of its year as it entered the second year of its Always Getting Better campaign, which bids to improve the firm's customer service.

The carrier said its planes flew 92 per cent full, up by six per cent on a year ago, while average fares fell four per cent to €45 euros (£32).

The airline lifted the number of passengers it expects to carry over the year from 100 million to 103 million, achieved by increasing business passengers and flying fuller planes.

However, it said it was "too early" to change its existing full-year net profit guidance of €940m to €970m, but added it expects profits will come in at the top end of its forecast.

In the winter it said it will take delivery of 31 new aircraft. It will also open new bases in Berlin and Gothenburg and begin flights to Israel for the first time.

Ryanair said as part of its customer service campaign it also expected to introduce new menus, new interiors and new staff uniforms this year.