His departure follows a string of major organizational changes at the agency, including Pam Hamlin taking the reins as the top executive after Robert LePlae left in December, among others. The agency works for clients like Milkbone, Hershey's and 23andme.
"I’ve taken great pride in establishing momentum in the Arnold, New York office with a range of quick and important new business wins, some internal reorganization, and strong client relationships,” Mitchell said in a statement.
The new business wins—including Kao USA, Volvo Trucks, DCH Auto Group and the cholesterol drug Alirocumab, a joint venture from pharmaceutical companies Regeneron and Sanofi—are said to be worth $12 million in new revenue for the agency.
“It’s been important to me to manage my exit proactively, minimizing impact on clients and our staff. I’m happy to be leaving on a high note and wish Arnold and our clients the very best. We agreed this earlier in the year—[I’ll remain] through May managing a transition and will announce a new position over the summer," said Mitchell.
"This decision was reached mutually," said a spokeswoman for the agency in a statement. "Corey made many terrific contributions to the agency both in new business and with current clients. We appreciate his work and leadership."
Other recent departures from the agency include chief creative officer Aaron Griffiths and chief digital officer Matt Howell, who both left in April. In January David Jones left his position as global CEO for parent company Havas and its namesake ad agency.