Radical plans by ministers to reshape Scotland's university system are dividing opinion among educationalists.
The NUS said the proposals would benefit the education system
The Scottish Executive is due to publish proposals to merge the funding councils for universities and colleges and to reconsider their status.
Universities Scotland director, David Caldwell, said he was concerned the move would be damaging.
But Rami Okasha, president of the National Union of Students Scotland, welcomed the possible change.
The proposals are designed to give colleges greater status and encourage people from poorer backgrounds to apply to university.
The executive, published the consultation document on Friday, rejected claims the move could see universities would change other than in the context of funding.
First Minister Jack McConnell said that suggest universities would be abolished was
He added: "We are proposing to merge two quangos into one. This will cut bureaucracy and allow more resources to be directed to students, universities and colleges.
"The institutional status of Scottish universities and colleges will not change at all."
Education chief Mr Caldwell said it was vital to preserve the tradition and mission of higher education in Scotland.
He told BBC Radio's Good Morning Scotland programme: "International reputation is a large part of it. If we fudge the difference between distinct missions of higher and further education, then we would buck a significant international trend.
"It's a distinction made all over the world which is vital. Anything that damaged our international reputation and limited our ability to attract international students to Scotland would be a problem."
Mr Caldwell said that with Scotland's population dwindling it was vital to ensure the country's universities could attract people.
He added: "We have to continue to talk about university, because university is a term used throughout the world."
Mr Caldwell said it was more important to maintain Scottish universities' reputations for producing world-class research rather than merging funding councils.
However, Mr Okasha said the NUS had been calling for such a move for the past 20 years.
He said: "We think the great divide in Scottish education is between compulsory and non-compulsory education rather than between students who go to college and university.
"We want someone who is studying the same course in college to be treated the same way as someone in university.
"So, an HND management course in college should be recognised as a first or second year university degree in management.
"They should be funded in the same way."
He said the higher and further education sectors could learn something from each other.
"There is no monopoly on good ideas in the education sector and everyone should learn from them together," he added.
Tom McDonnell, president of the Association of University Teachers Scotland, said: "The reputation of our world class universities will be lost if these proposals go ahead and the artificial barriers proposed will set the sector back 12 years to the point when the formation of new universities broke down the binary divide.
"University lecturers undertake a diversity of roles and have a range of very high level qualifications, both academic - such as a doctorate - and professional qualifications in their specific subject area.
"Specific training in teaching methodology is widely available and encouraged but a legislative requirement to undertake a specific teaching qualification is totally unnecessary.
"I am concerned that these proposals will not tackle the problems of social access but instead restrict the excellent four year honours degree to the privileged few."