She joins as UK entertainment director. She replaces Marc Berry Reid, who takes on a wider role as associate director concentrating on European operations.
Pettitt will lead a new offline and integrated team at Way To Blue and will report to Berry Reid.
At Diffusion, Pettitt helped establish the film and entertainment practice, which launched in 2010.
Diffusion declined to comment on Pettitt’s departure or the future of its film and entertainment division. Pettitt has yet to be replaced, PRWeek understands.
Diffusion and Way To Blue have both worked on campaigns for clients such as Lionsgate and StudioCanal on a project basis.
Way To Blue has also hired Daniel Heale, former head of marketing for Vue Entertainment and Camelot Group, as associate director of social. He will head social analytics, strategy, engagement campaigns and community management.