Ell85,
Several UK airlines had fully sponsored cadet programmes on JAR-FCL Integrated courses until the attacks of 11 September 2001 put the industry into a slump. At that time, the likes BA, BMI, Aer Lingus and others canceled the courses for many cadets and sent them home. The age limit was usually 18-27 or so. In fact, I'm pretty sure that John Monks, BAs current recruiter was 19 when he finished training and BA CEO Willie Walsh was 17 when he started training.
As the UK industry began a slow recovery from 9/11, the recruiters discovered there were plenty of students already on integrated courses paying for their own training. As a result, they have not yet experienced enough difficulty recruiting new FOs to see the need to restart funded cadet programmes. Since they have many years experience with suitably mature and well trained 18 and 19 year olds doing the job well, there's been no increase in the age requirements in these post sponsorship days. furthermore, on 1st October 2006, anti-ageist legislation went into effect in the UK, though this is probably more meaningful to older wannabes.