Derek Morris, the agency's chief strategy officer, has been handed the additional role of chairman of the agency, a post that has been vacant since Simon Marquis stepped down.
Tim Neligan, ZenithOptimedia's commercial director, has been promoted to managing director. Neligan, a former joint managing director of CIA UK, joined ZenithOptimedia in May 2004 after a spell as a consultant.
Mark Waugh, the agency's deputy managing director, will continue in the role and will work closely with Boyle on developing new services.
Chris Hayward, the agency's head of broadcast, has been promoted to head of investment and will oversee all of the agency's buying.
Mark Howley, previously a managing partner, takes on the new role of head of planning and client service. Alongside Morris, he will take on the task of developing planning talent at the agency. Boyle said: "Mark's promotion is a bid to regain a single-minded focus on planning."
Boyle, who was promoted to the role of chief executive in June following the departure of Antony Young, said of Morris: "I'm looking forward to drawing on his experience."
Morris has been with ZenithOptimedia since June 2004 after a stint at sister agency Publicis. Previously, he was a founder of the communications planning agency Unity.
Boyle added that Neligan's commercial strengths will be an asset: "Tim has lots of good, wide experience, and balances my skill-set tremendously."
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