ROME--Mediaset SpA (MS.MI) said on Thursday that it has appointed as its chief executive Pier Silvio Berlusconi, a son of the founder of Italy's biggest broadcaster by market value.

Mr. Berlusconi, 46, replaces longtime CEO Giuliano Adreani, 72. In a statement, Mediaset said Mr. Adreani will assist Mr. Berlusconi in the company's strategy for the advertising market.

Mr. Berlusconi keeps his role of vice chairman at the Milan-based broadcaster.

His father Silvio Berlusconi, a former Italian prime minister and head of the center-right opposition party Forza Italia, controls Mediaset via the family holding company Fininvest.

Write to Liam Moloney at liam.moloney@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires