Ann Watson (pictured), who heads Semta, the not for profit employer-led body tasked with skilling engineering and advanced manufacturing, said it could be an early indicator that the skills gap is widening.
Another unintended consequence is to raise the age of apprentice applicants, as older people fill the vacancies, she said.
Over 25s already account for the largest number of apprentice starts in the last year, a total of 161,600, with 16-year-olds lagging behind at 25,500. "This might be bad news for business," said Watson. "The door to university is being opened even wider which may mean school leavers will get swept in without considering fully their options.
"Meanwhile industry is crying out for apprentices to fill positions that will provide opportunities to earn and learn, solid qualifications and a rewarding career for life."
She added: "The Government has set itself of a tough target of creating three million new apprenticeships in this Parliament which will take some doing. The engineering sector needs a further 800,000 skilled engineers by the end of the decade to fulfil its growth potential so there is no time to lose."
The Government has lifted the cap on university places resulting in more than 400,000 youngsters being accepted on courses with a further 100,000 likely to find places between now and the start of term.
Meanwhile, commenting on yesterday's A-level results, Verity O'Keefe, senior skills policy adviser at EEF, said they presented a mixed bag for business: "Industry applauds all those young people who have chosen to study challenging STEM subjects and the 4% jump in the number of young people taking maths at A-level is encouraging.
"But there are some worrying trends, including minor decreases in the numbers achieving top grades in subjects like physics, maths and chemistry and a dip overall in the number of students taking the sciences."
She added: "Government, schools and industry need to work harder to encourage more girls to take up STEM subjects. While the gap closed slightly again for physics the pace is too slow and, for maths, the gender gap has actually widened.
"The door to a career in manufacturing is wide open for young people, especially those that have made the grade in the sciences and maths. But manufacturers can only grow and prosper when they have ready access to a wide pool of talent. Without greater encouragement for girls to take up key subjects such as maths and physics, that pool remains worryingly shallow."
