He will be based in the group's Miami office.
Ortiz will take over the role on 1 July and will run Burnett's 18 offices across South America. He will work with the agency's regional creative director, Alexandre Okada, while continuing as the worldwide creative head on the network's Procter & Gamble business.
Zandomenego is retiring from the industry after 36 years. He became the group president in 2002, having been the managing director of Burnett's San Juan office, and president of its Caracas office.