Ryanair is set to allow customers on all its flights to reserve seats, the no-frills carrier has told The Independent. In a radical departure from usual practice, the airline said trials of a €10 \"book-a-seat\" service between Dublin and Gatwick and Dublin and Malaga launched last month had proved to be far more successful than expected. The move, believed to be the first by a budget air travel carrier, comes as airlines are closely scrutinised. Hidden extras charged by low-cost airlines are being probed by the Office of Fair Trading, which is due to report its findings in the next few weeks. Caroline Green, Ryanair\'s director of customer service, said an extension of the scheme would take place on another route this summer and a decision on whether to extend the service to all 165 destinations the company flies to was likely to be taken in September. In the past Ryanair has not been afraid to try new charging models. In 2009 its chief executive Michael O\'Leary said the company was considering charging £1 to use the toilet.