Over-18s joining the scheme are outnumbering the 16 to 18-year-old entrants for whom Modern Apprenticeships were devised. National Training and Enterprise Council officials say that, increasingly, today's Modern Apprentices have A-levels, or even degrees.
The changes raise the prospect of state-funded schemes subsidising companies' graduate and post-A-level training.
But the TECs, which have a responsibility to guarantee training to 16-18-year-olds, welcome the trend, arguing that the scheme was providing much needed vocational training for those with a wholly academic background.
Mary Lord, TEC National Council education and training policy adviser, said: "We will start seeing people from higher education using modern apprenticeships to transfer their knowledge to the work environment.
"Modern apprentices might come in with a degree in business studies and then go into a modern apprenticeship to get the competence that gives evidence of applying that skill. In theory they could get funding up to the age of 24."
The past year has seen a massive increase in the proportion of over-18s starting Modern Apprenticeships.
During the 1995-96 academic year 15,298 teenagers aged 18 or under signed up for the scheme, compared with just 431 over-18s.
But a year later 17,595 over-18s signed up, overtaking the 17,098 in the younger age group.
The TEC National Council believes that funding beyond the age of 18 will help push national vocational qualifications and underline the high quality of training in the Modern Apprenticeship scheme.
Ms Lord said: "It's extending the use of NVQs across the workforce. We want to increase the take-up of Modern Apprenticeships which bring high quality training."
The training manager of a leading high-street bank commented: "We won't be taking it up because we no longer have a blanket recruitment programme for A-level entrants and the age cut-off for funding is too tight a timescale for our graduate training programme.
"Modern Apprenticeships make more demands on the employer than an NVQ because you have systems in place for assessing internally - increasing the workload of supervisory managers - or externally which involves extra cost."
But other sectors of business are more keen. A managing director of a design and marketing company who was considering modern apprenticeships for his graduate recruits commented: "A problem we often have with graduates when they first come to us is that they think a lot of what we ask them to do is boring and mundane. Vocational training would force them to apply their brains to the practicalities of the business."