Ryanair chief executive Mr Michael O'Leary could make up to £40 million (€51 million) if he sells six million shares in Ryanair later this week. Mr O'Leary is selling five million shares as part of the placing but may dispose of an additional one million if demand is high.

However, Mr O'Leary still retains almost 10 per cent of the company, valuing his stake at almost £200 million. Ryanair chief financial officer Mr Howard Millar said Mr O'Leary had sold shares in the company at every placement since 1997. "He is just realising some of his investment in the company which is a normal thing to do," he added.

Mr O'Leary qualified as a chartered accountant, working initially with KPMG (then Stokes Kennedy Crowley), before going into business on his own. He later became personal adviser to Dr Tony Ryan, founder of GPA before becoming involved in the family's airline business.