Whalar Group, creator ecosystem company, names co-founders Neil Waller and James Street co-CEOs, effective immediately, and hires Edelman’s Christoph Becker as its first chief creative officer; current CEO Rob Horler to relinquish his role, returning to Whalar board, effective May 1 ... MediaCo acquires all of Estrella Media’s network, content, digital and commercial operations, and taps New Majority Ready’s Jacqueline Hernandez, also former Telemundo chief operating officer and ex-NBCUniversal Hispanic Enterprises chief marketing officer, as interim CEO of the combined assets ... Mitel hires Bill Dunnion, ex-Calian Group, as chief information security officer ... MainStreaming, media delivery platform, hires ex-Joyn CEO-Chief Technology Officer Tassilo Raesig, also former Sony Europe head-digital and media strategy, as chief operating officer ... InfoVision, IT services company, adds Live Earth Chairperson Radhika Venkatraman, also former 20-year Verizon veteran, to its advisory board.