David Gibson, chief executive of the Association of Colleges, called for all colleges and universities to review current partnership arrangements so that students opting for a broader post-16 curriculum are fully supported once they enter higher education.
Colleges are frustrated that universities have still not announced what admissions criteria they will use once students who have followed the new curriculum start applying for HE places in 2002.
From next year, in addition to revised A-levels and General National Vocational Qualifications, students will be able to take new-style AS-levels and a new key skills qualification.
Speaking at a conference on the post-16 changes held in London this week, Mr Gibson said he had not seen much evidence of joint planning between colleges and universities.
"We need clearer and supported progression. We need to look at whether FE colleges can play a wider role in continuing student support with you in partnership," he told HE admissions tutors.
In spite of the Government's support for broader post-16 studies, colleges fear that students with few or no A-levels will still be less likely to gain places at leading universities. A new advanced extension award, which is to replace S-level exams, will only be available to students taking A-levels.
Sue Williamson, vice principal of Peter Symonds College in Winchester, asked education minister Baroness Blackstone how she will ensure that so-called "selective universities" take the reforms on board.
"If you are going to use the advanced extension award as the means of getting into the best universities then you are going to create a very divisive system," said Mrs Williamson.
Baroness Blackstone replied that the award was only likely to be taken by a minority of most-able students and is not designed to be a central part of the changes. She hoped, however, that the take-up would be higher than for S-levels. "I will be doing my best to encourage universities to take these reforms very seriously," she added.
A survey by the Committee of Vice-Chancellors and Principals showed that, while universities are still in the dark about the changes, they are broadly in favour of broadening studies in school sixth forms and FE colleges.
CVCP vice-chair Professor Roderick Floud said prestigious universities preferred to recruit rather than select students. "We are interested in using a wide range of evidence," he told the conference. "Universities don't wish to be conservative and won't be conservative in response to these qualifications."