You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
Warriors board member Rob Croot has been appointed to step up as the NRL outfit's new chairman, while McGregor has dropped down to become deputy chair.
Croot is managing director of Autex Industries, who in May became part-owners of the Warriors, together with the Carlaw Heritage Trust.
Autex took on a 33 per cent share in the club when the partnership purchased the Warriors from former long-time owner Eric Watson.
McGregor was also chairman of the ARL but in stepping down from his elected post has effectively pulled the pin on any involvement with the regional organisation.
He is also chairman of the Carlaw Heritage Trust and is remaining on in that role.
Since Autex and Carlaw Heritage Trust took control of the Warriors, McGregor has been under pressure to relieve himself of at least one of his three titles.
The ARL only learned of McGregor's decision to resign from all duties today.
It's understood the ARL board will determine who their new chair is, with deputy Shane Price in the box seat to replace him.
"I have stood down as chairman of the Warriors and stood down completely from the ARL board," McGregor confirmed to the Herald.
"There's a very capable replacement at the Warriors with Rob taking over and I'll still be on the board as deputy.
"I had intended standing down from the ARL board completely because the chairman is an elected position. I've been there for 16 years and I just felt that now was the right time for that to happen.