Ambika Srivastava is new IMX chairman

India Media Exchange (IMX), media negotiation unit formed in 2007 to leverage the combined assets of Starcom MediaVest Group and ZenithOptimedia, has named Ambika Srivastava as its new chairman. Srivastava (pictured), CEO of ZenithOptimedia, fills the void left by Shyam Shankar who quit as IMX's president in May 2008.In another development, VivaKi, the strategic unit created by Publicis Groupe to leverage the combined scale of its media and digital operations, named Srikant Sastri, managing director of Solutions Digitas as its India country chair.