Ryanair pricing attacked.
John Fingleton, chief executive of the OFT, attacked the company for fees that could be added when customers pay online.
He singled out the practice of levying fees by adding charges to payments made with a specific type of bank card.
And he also questioned the automatic addition of insurance to flights by airlines such as Ryanair - the biggest operator from JLA, in terms of route numbers - unless customers opted out.
Earlier this year, following OFT intervention, Ryanair promised to take steps to increase the clarity and transparency of its website and other advertising.
Ryanair Head of Communications Stephen McNamara said: "What the OFT must realise is that passengers prefer Ryanair's model."