The group carried almost 5.8 million passengers in August – an increase of 19 per cent on a year earlier – while it filled 90 per cent of available seats.

Ryanair said it had increased passenger numbers every month this year, taking the total for the 12 months to August to 55 million.

The airline has refused to introduce a fuel surcharge, in spite of warning in July that it could turn in a full-year loss because of high oil prices.

It also said it anticipated a five per cent fall in average fares this winter.

Head of communications Stephen McNamara said yesterday: "Our rapidly-growing passenger numbers come at a time when many airlines, which are facing huge losses, are raising fares and fuel surcharges in an attempt to turn these losses around."

The load factor of 90 per cent was lower than the 91 per cent seen a year earlier, but Ryanair said this was due to an increase in capacity over the last 12 months.

Ryanair recently fixed 90 per cent of its fuel requirement at $129 a barrel for September and 80 per cent of the October to December period at $124 a barrel.

Oil prices have since fallen to below $110 a barrel, while Ryanair said in July it was unhedged for the fourth quarter to the end of March.

August traffic figures released by British Airways on Wednesday showed a 2.7 per cent fall in its load factor compared to 12 months earlier.

Premium traffic rose 2.2 per cent – compared with a 2.1 per cent fall in non-premium travel – but BA also warned that the outlook for premium travel remained "uncertain" until after the summer break.

The total number of passengers carried by the airline fell 3.2 per cent to 2,988,000 compared to the figure in August last year.

Low-cost airline easyJet, founded by Stelios Haji-Ioannou, is due to publish its traffic figures today.