Michael Thomson told Brumbies staff of his decision to resign at an emotional meeting on Monday morning. He will finish his tenure on October 19, despite having 12 months remaining on his contract.

His successor will come from within, albeit from an unusual position. Chairman Phil Thomson will resign from the board to become the club's chief executive.

It continues a revolving door for the Brumbies' top job, with the club having six chief executive changes since Andrew Fagan quit at the end of 2013.

Fairfax Media can reveal Phil Thomson was appointed to the role at the same meeting Michael Thomson stood down in when the board met on Thursday last week.

One of the directors suggested Phil Thomson as a leadership candidate, and at that point Phil Thomson and Michael Thomson were excused from the board meeting. The directors then made a unanimous decision to offer the job to Phil Thomson.

It is expected Phil Thomson, a former Brumbies interim chief executive and Rugby Australia integrity manager, will sign a three-year deal in the hope it will give the club stability.

The exact contract terms are yet to be finalised, but Phil Thomson will start in the position on October 22.

"It came as a surprise to everyone that Michael was going to resign because he genuinely loves the organisation," said interim Brumbies chairman Matt Nobbs.

"We've had five CEOs in five years ... it's not a good look to be going to market and the time issue. Phil has been in that role before ... he knows it and he's got good relationships with our stakeholders. It's just a good fit."

The decision to act so quickly on appointing Phil Thomson was due to a number of factors, including coach and player contracts, and looming sponsorship decisions.

Brumbies coach Dan McKellar's deal expires at the end of next year and player negotiations for 2020 and beyond need to start immediately given a host of stars are off contract at the end of 2019.

The Brumbies also wanted to avoid a period without someone in charge, like has been in the case in the past. The Brumbies have had five chief executives - Fagan, Doug Edwards, Michael Jones, Phil Thomson and Michael Thomson - since November 2013.

"The board wanted to make the transition as smooth as possible, understanding the hole that Michael would leave," Phil Thomson said.

"The fact I was interim CEO from May-December 2016, was a director for 12 months and a chairman for 12 months, I know the business very well and the key stakeholders.

"I'm very happy to step into the role and I look forward to it. I do have a good understanding of where we've come from, where we are and what still needs to be done.

"There's still a lot that needs to be done. It is a tough environment, but I'm happy to take on the role to continue the good work Michael has done.

"Michael has done a great job. He's very passionate about the club and about rugby in the region. We respect his decision to step down, but he'll be sorely missed."

Australian Super Rugby clubs have struggled in the past two years, with uncertainty in the competition format affecting interest, crowds and broadcast figures.

But rugby union participation in Canberra has grown by seven per cent in the past 12 months and the Brumbies are regarded as financially stable after profits of $14,000 last year and $52,000 this year.

It will be the first time in a decade the Brumbies have recorded profits in back to back years and puts an end to losing more than $3 million in the three years prior to Michael Thomson's arrival.

But Michael Thomson says the time is right for another shift after helping the Brumbies mend broken bridges and find financial stability in the past two years.

"It was an extremely hard decision. It's not something I made quickly or lightly," Michael Thomson said.

"I came back to the club because I wanted to help stabilise it, to help overcome some of the challenges in recent past. I look at where the organisation is at now ... I thought this is a good time for me to hand over to an incoming chief executive.

"It gives them a long runway to grow the organisation and there's not quite the same immediate pressures than when I came on board."