Kevin Dundas, the chief executive of Droga5 Europe, has left the agency 18 months after he helped launch it.
Dundas and the executive creative director, Nik Studzinski, were hired to open the London office in April 2013.
Dundas worked with David Droga, Droga5's founder, when the latter was executive creative director of Saatchi & Saatchi London, between 1999 and 2003.
During that time, Dundas was executive planning director before becoming the managing director. Dundas was then the chief executive of the Saatchi & Saatchi UK Group between 2003 and 2005.
"Kevin and I have a long work history and friendship," Droga said. "He had the hard task of setting up the agency and giving it its initial momentum, but in this crucial and tough market we now need to operate in a different way.
"Kevin is more than just a great talent, he is one of my favourite people in the industry. I will always be thankful to him," Droga said.
"I want to build the most influential creative agency in the world, and we’re our biggest critics. We need to earn our reputation here; I want London to inspire and validate our mission for our clients."
Dundas' successor at Droga5 Europe has not yet been named. Dundas was unavailable for comment.
This article originally appeared on campaignlive.co.uk.