Duff will replace Mick Desmond, currently chief executive of Granada Enterprises, who has been promoted to managing director of Granada Broadcasting and Enterprises, a newly created position within the company.
Steve Morrison, chief executive Granada Enteprises, said, "Granada's businesses will now be streamlined into two divisions, one managing broadcasting and enterprises, and the other managing all content-associated business."
Simon Marquis, managing director of Zenith Media, has been promoted to become the new chief executive.
Duff joined Zenith in 1993 and was made its chief executive in 1997, where he was responsible for all Zenith UK Group companies.