The appointment was expected after Vincent Bollore, the Havas chairman, told ±±¾©Èü³µpk10 in May that Alfonso's name was to be put forward for approval by the Havas executive committee.
Alfonso has been at MPG for 10 years, having joined in 1996 as head of corporate development after a period in merchant banking.
In 2001, he was appointed CEO of MPG Spain and Southern Europe and CEO of MPG's sports network Havas Sports in 2001.
His ascension to the helm of MPG comes four months after his brother Fernando was appointed chief executive of its parent company Havas.
Alfonso said: "This appointment represents the continuation of our commitment to the future of both MPG and Havas. The current media landscape is filled with opportunities and I look forward to working with our management teams to ensure that we continue to drive the company and its people forward."
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .