The Welsh Assembly has been warned it needs to spend an extra pound;4million a year to train lecturers if standards are to be maintained.
The Further Education National Training Organisation says it found under-funding during its research into workforce development in Welsh colleges.
Wales, like England, now insists on qualifications for new lecturers, a move which Fento welcomes. But it says there are still weaknesses, particularly in developing lecturers already in post.
It says lecturers need more training on how to teach "disengaged" students; an awareness of awarding body requirements and staff management.
Fento predicts that lecturers will be working with an increasingly wide range of students and need a wider variety of teaching methods.
Gavin Thomas, Fento's national development officer for Wales, said: "No profession can afford to stand still. Continuing development is essential if standards are to be maintained."