Reports in the Italian press suggest that the 34-year-old goalkeeper is set to extend his deal in Turin until 2016.
And Marotta does not expect any problems given Buffon's on-going importance to the club.
"It seems to me the president has already cleared what is the current situation, that's to say that between Juventus and Buffon there aren't problems for the negotiation", Marotta told Sky Italia.
"Buffon is Juventus and so he could stay at this club as long as he wants. So the contract could become a formality. We will have time to officially announce the deal in the next few weeks."
The World Cup-winning keeper has been with the Bianconeri for over a decade since joining from Parma in the summer of 2001.