The transition was announced in April when Habets, 46, was named co-CEO. De Posch, 60, had headed RTL Group since 2012 and had expressed the wish to stand down after six years at the top.

"I simply believe that now is the right time – both for a change at the top of RTL Group and for me to focus on new things in life," de Posch told staff in a farewell interview.

"This is a smooth transition in RTL Group's leadership, and this continuity is one of our key strengths: promotion from inside."

RTL, controlled by Bertelsmann, has, thanks to its greater focus on producing its own content, has gained share in the key German market against rival ProsiebenSat.1, whose own CEO Thomas Ebeling is standing down after a series of downgrades to its advertising and earnings forecasts.

Habets joined Luxembourg-based RTL Group in 1999 and became CFO of RTL Nederland in 2001, rising to become CEO of the Dutch business in 2008.

Elmar Heggen will remain CFO of RTL Group and become deputy CEO, taking over portfolio responsibility for Groupe M6, the French broadcaster, and RTL Belgium on behalf of RTL's executive team, the company said in a statement.

De Posch will assume the role of non-executive director at RTL Group.

(Reporting by Douglas Busvine, editing by Louise Heavens)