Long-time Publicis media chief Jack Klues -- one of the most powerful and highest paid media executives on Madison Avenue -- will retire as CEO of its centralized VivaKi unit at the end of the year. Klues, who will remain with Publicis Gorupe through the first half of 2013, will help oversee a repositionng of VivaKi, which to date has primarily serviced its founding Publicis shops -- Digitas, Razorfish, Starcom MediaVest and Zenith Optimedia -- to be available more broadly to other Publicis agencies and the market at large.