Nine Entertainment Co chairman and former federal treasurer Peter Costello has resigned from his role and stepped down from the company’s board.

Costello, who was appointed in 2016, will be succeed by current deputy chair Catherine West, who has worked in the media and entertainment industry for over 30 years in the United Kingdom, Europe and Australia.

In an email to all staff on Sunday afternoon, Nine CEO Mike Sneesby said the board wished to thank Costello for his contribution to Nine over more than a decade, including eight years as chairman.

“Mr Costello played a key role in Nine milestones such as its successful re-listing on the Australian Stock Exchange in 2013, securing the landmark news media bargaining code and the transformative merger with Fairfax Media,” Sneesby said.

“I want to thank Peter for his contribution to Nine over more than a decade.

“As the announcement makes clear, he has played an important role in the big Nine milestones over that time – a period marked by dramatic digital transformation for the media industry and our company.

“Our deputy chair Catherine West has been appointed as chair and will lead existing plans for board renewal.

“It has been a challenging few weeks for our company and I want to express my heartfelt appreciation to all of you for your hard work.”

Costello thanked the board for their support over the last decade and particularly during the events of the last few weeks.

“After nearly eleven years on the board of Nine Entertainment Company (NEC) and more than eight years as chair, I had flagged retiring from the board some time after the July Olympics and by the AGM in November at latest,” wrote Costello.

“Last year, the company retained a search firm to identify new directors. The work is well advanced.

“I have today informed the board of NEC that I will pull forward that timing, stand down as chair and resign as a director.

“The deputy chair Catherine West has been working with the search firm and is well placed to chair the company and conclude the process of refreshing the board.

“The board has been supportive through the events of the last month and last few days in particular. But going forward I think they need a new chair to unite them around a fresh vision and someone with the energy to lead to that vision for the next decade.”

West added: “On behalf of the board I want to thank Peter for his dedication and commitment to Nine.

“Peter has led the transformation of Nine from a free-to-air network to a fully integrated media company with traditional and digital media assets across television, streaming publishing, audio and marketplaces.

“As chairman, he has always put the needs of the company first and his decision to stand down and pass on the baton of leading Nine at this time is in line with that approach.”

Costello was treasurer of the Commonwealth of Australia from March 1996 to December 2007, and was the longest serving treasurer in Australia’s history.

Last week Costello denied assaulting a journalist who was asking him questions in Canberra Airport about Nine’s handling of allegations following the departure of TV news boss Darren Wick.

Nine is the publisher of this website.