The 24-year-old is out of contract in the summer and he is ready to leave France for a new challenge.
Southampton and Watford have both been linked with the France international, while clubs in Germany are keen too.
However, according to L'Equipe, it is Swansea who are making progress over a January move for Ntep.
The Welsh club's new boss, Bob Bradley, is keen to bolster his squad during next month's transfer window and he has identified the Frenchman.
Rennes are aware of Ntep's reluctance to sign a new deal and as such they are ready to let him go in January - rather than lose him for free in the summer.