iiNet founder and former CEO Michael Malone has replaced former colleague Simon Hackett on the board of NBN.
Malone this week joined the NBN board as a director for a period of three years as a replacement for Hackett, who has resigned to focus on his role as executive chairman of ASX-listed battery maker Redflow Limited.
Hackett is the founder of internet service provider Internode, which was bought by iiNet for $105 million in 2011.
He today said he leaves the NBN board with a sense of regret.
"I will greatly miss the experience of being in the midst of something so very pivotal, in a space I care about so much," Hackett said in a statement.
"It has been a privilege to be a part of such an endeavour and I would jump at the chance to return if future opportunity should arise.”
NBN chairman Dr Ziggy Switkowski said Hackett had been a "critical" member of the NBN board.
"There are few such individuals who match the specific needs of NBN so well at this stage of its development," he said in a statement.
Hackett had been a somewhat controversial NBN director, arguing the federal government's fibre-to-the-node policy "sucked" and saying he wished it would disappear.
Communications Minister Mitch Fifield and Finance Minister Matthias Cormann today thanked Hackett for his "valued contribution" and welcomed Malone in his place.
The ministers said Malone brought "strategic acumen, business development and management experience" to the NBN board.
Switkowski said Malone's experience would bring "new perspectives to the board table" and help fill the gap left by Hackett's departure.
Malone left iiNet in March 2014 after 20 years with the business. iiNet was bought by TPG the next year.
Since leaving iiNet, Malone has taken up directorships with the likes of Seven West Media, Superloop, SpeedCast and - before its collapse - Yatango.
He also invested in and serves as the chairman of IT security service provider Diamond Cyber.