Guy Wieynk is stepping down from his post as chief executive of Publicis Worldwide UK and western Europe.
Wieynk, who joined the agency in January 2015 after 18 years at AKQA, leaves next month. He is not believed to have another role to go to.
It is understood that Publicis will not be looking to appoint a direct replacement, with Nick Farnhill continuing in his role as chief executive of Publicis London and Poke.
In a statement, Publicis credited Wieynk with leading the "turnaround and resurgence" of Publicis Worldwide UK and helping to bind its constituent agencies – Publicis London, Poke, Arc, August and 82 Baker Street Productions – into a "strong, multidisciplinary" business.
Client wins during Wienyk's tenure include Morrisons, Lastminute.com, the International Olympic Committee and Heineken. He also operated as global client lead on the latter.
Wieynk commented: "I am very proud to have contributed to the transformation of the Groupe and to have led the turnaround of Publicis Worldwide in the UK. Nearly four years on, the Publicis UK transformation is complete and I am leaving a strong multidisciplinary business in the very capable hands of Nick Farnhill. I wish Nick and the team every success in the future."
Annette King, chief executive of Publicis Groupe UK, added: "Guy’s leadership has been integral to a successful transformation in the offering across Publicis UK agencies. I would like to thank Guy for his commitment and wish him all the best in his next chapter."
Wieynk becomes the second senior figure to leave the business this year, following the departure of Publicis London chairman and Publicis UK chief client development officer Karen Buchanan in May.