Nine is also the owner of The Sydney Morning Herald and The Age.
In an email to staff on Tuesday morning, Mr Malone wrote that growing up, he had loved watching cricket and rugby league, one day hoping to see his name on the list of credits one day.
“This team is the best in the business. But it’s not until you get to Wide World Of Sports that you realise it’s made up of wonderful people on the inside. It is a very special place to work because of you – the people who love sport, love broadcasting and care greatly for each other,” Mr Malone wrote.
“I am sad to be leaving this great group of people, but excited about a great new challenge for our business, and of course happy I’m not leaving the family entirely.”
“I’m excited to be returning to radio,” Mr Malone said in an additional statement from Nine. “2GB, 3AW, 4BC and 6PR are all powerful voices in their respective cities with deep connections to their communities, and we will seek to expand on that.”
“The move to full ownership of Macquarie opens up real opportunities to build on that foundation and creates new ones to engage with listeners in each state.”
Mr Malone’s replacement is expected to be announced in the coming days.
Nine has confirmed he will have oversight of the radio division, while Macquarie’s newsrooms will fall under Nine’s Director of News and Current Affairs Darren Wick.
Mr Malone will work closely with Nine’s local managing directors to seek more opportunities for growth and integration across the wider Nine business, the company said in a statement on Tuesday.