The Italian took on the global CEO role - then a new position - in October 2005. He joined from MEC, where he was global CEO.
Robert Lerwill, the CEO of Aegis, said in a statement: "I would like to thank Mainardo for all he has done during his time at the helm of Aegis Media. He is a true professional and he has our gratitude. We wish him the very best in his future endeavours."
Patrick Stahle, the CEO of Aegis Media Asia Pacific, said: "Mainardo has done a good job of putting Aegis Media on the map as a global entity. Jerry is a great choice to take us to the next level."
"I have known Jerry for 13 years. He's a great client man and has a stunning new business record in Europe, recently winning Johnson & Johnson and General Motors. He will increase our capacity to win global business, which is very important for us in Asia Pacific."