Alex Mahon will become chief executive of international producer and distributor Shine Group from September.
Mahon, who was previously president and chief operating officer, Shine Group, will oversee the daily management of all 28 companies operated by Shine Group.
She replaces founder Elisabeth Murdoch, who will remain as group chairman.
Murdoch said: “Alex has earned this new leadership position in recognition of her substantial contribution to Shine’s growth,” adding that Mahon’s duties will involve “managing the operational aspects of the company and allowing me to concentrate on identifying future strategic opportunities”.
Mahon joined the Shine Group in 2006 after a spell as chief operating officer of Talkback Thames.