Ross Neil, executive creative director of McCann London, has left the agency after less than one year in the post.
A spokesman for McCann said he had left to "pursue new opportunites".
Neil joined McCann London in June last year, four months after he left WCRS, where he had spent 11 years, most recently as joint executive creative director. Neil was brought in to run McCann's creative department alongside chief creative officers Rob Doubal and Laurence Thomson.
The spokesman added: "During his tenure as ECD at McCann London, Ross brought an enthusiastic level of energy and experience to the creative team, reporting directly to McCann UK CCOs Rob Doubal and Laurence Thomson. We appreciate all that Ross has contributed during his time at McCann and wish him all the best in his future endeavours."