Media tycoon Rupert Murdoch is to retire as chairman of his Fox and News Corp businesses.

The Australia-born businessman is set to be replaced in the role at both companies by his son Lachlan Murdoch.

The change of leadership will take place following the companies’ annual meeting in mid-November.

The 92-year-old will be appointed chairman emeritus of each company.

In a letter to staff, he said “the time is right for me to take on different roles”.

He added: “I am writing to let you all know that I have decided to transition to the role of chairman emeritus at Fox and News.

“For my entire professional life, I have been engaged daily with news and ideas, and that will not change.

“Our companies are in robust health, as am I.

“Our opportunities far exceed our commercial challenges.

“We have every reason to be optimistic about the coming years – I certainly am, and plan to be here to participate in them.”

Mr Murdoch launched his media career in 1954 by taking control of Australian publisher News Limited, which was previously run by his father Sir Keith Murdoch.

The group rapidly expanded internationally, which included a deal to buy the News of the World and Sun newspapers in the UK in 1969.

In 1986, he launched the Fox Broadcasting company in the US and started the Fox News station ten years later. It is now the most popular news network in the US.

Lachlan Murdoch said: “On behalf of the Fox and News Corp boards of directors, leadership teams, and all the shareholders who have benefited from his hard work, I congratulate my father on his remarkable 70-year career.

“We thank him for his vision, his pioneering spirit, his steadfast determination, and the enduring legacy he leaves to the companies he founded and countless people he has impacted.

“We are grateful that he will serve as chairman emeritus and know he will continue to provide valued counsel to both companies.”