Argentina's Marcelo Rodriguez will take over as Sanzaar chairperson effective immediately, the governing body of southern hemisphere rugby announced on Friday.
Sanzaar also said Australian Brendan Morris had been promoted to chief executive from chief operating officer. He replaces Andy Marinos, who was recently named Rugby Australia's new CEO.
Rodriguez, the current president of the Argentina rugby union, said his appointment reflected the South American nation's growing standing in the game.
"In recent times. we have seen Argentina rugby grow stronger and produce some great performances and this appointment is a clear demonstration of the respect and international prestige achieved by Argentinean rugby all over the world," he said.
Rodriguez replaces New Zealander Brent Impey, who resigned last year.
Sanzaar was set up in 1996 to manage the Super Rugby club competition and the Test tournament now known as the Rugby Championship.