After 14 years with the Paris-based company, Vincent Chalvon-Demersay has decided to step down as CEO of Zodiak Media-owned Marathon Media citing personal reasons.

As a result, Marc-Antoine d’Halluin has been appointed acting CEO of Marathon Media, a title he will hold temporarily, along with his current role as Zodiak Media’s CEO, a job he took in October after David Frank stepped down.

Chalvon-Demersay’s decision was effective November 17, and the animation industry veteran plans to sell his shareholding stake back to Zodiak Media. During the transition, he will remain on with Zodiak’s Los Angeles office.

After co-founding Marathon in 1999, with its current general manager David Michel, Chalvon-Demersay moved from an MD role to become an executive committee member of Marathon Group in 2005 until its sale to Zodiak parent company De Agostini in 2007. He also served as Zodiak Media’s chief strategy officer from 2012 until exiting the position earlier this year.

Chalvon-Demersay, in partnership with Michel, achieved international success creating and producing hit animated kids series such as Totally Spies! and Martin Mystery.