The National Broadband Network Co's (NBN) Chief Mike Quigley has welcomed the appointment of Siobhan McKenna as the company's new Chairman.

“It’s a pleasure to welcome Siobhan to the role of Chairman. Her track record on the board over the past four years, her strong business advisory background and her clear grasp of the scale and complexity of Australia’s largest national infrastructure project will be of great benefit as we continue to roll out the NBN across the country.

Ms McKenna's appointment comes after outgoing Chairman Harrison Young announced he will not run for reappointment after his three year appointment expired last week.

“I am also honoured to pay tribute to Harrison Young upon his retirement from the Chairmanship and the Board. I want to pass on our sincere thanks to Harrison for his strong stewardship of the company over the past three years along with our very best wishes.

Ms McKenna brings extensive experience to the role, having served on the NBN Board for three years.  She is also a director on the board of Ten Network Holdings, DMG Radio Australia, Illyria Pty Ltd and the Australian Ballet. Ms McKenna has previously served as a Commissioner with the Productivity Commission, a director with Prime Media Group and a partner with McKinsey & Company.