Larkham is set to sign an extended three-year deal to take on all responsibilities of leading the Brumbies rugby program, offsetting the departure of director of rugby Laurie Fisher.

It is understood the Brumbies will announce Larkham's new role and contract on Sunday, as well as confirming Fisher's defection to coach Gloucester in the United Kingdom next year.

The Brumbies have set up a committee to search for a replacement for Fisher for next year and beyond, the club deciding how to best support Larkham in his new role.

Larkham and Fisher joined forces as a coaching duo this year, Larkham taking on head coaching duties and control of the backline, while Fisher oversaw the Brumbies program and forwards. Both signed two-year deals, but Fisher will be granted an early release.

Larkham's new role will make him the sole man in charge for the 2015, 2016 and 2017 Super Rugby seasons.

Larkham has led the Brumbies' retention campaign which has resulted in Matt Toomua, Nic White, Christian Lealiifano, Joseph Tomane, Jesse Mogg, Scott Fardy, Henry Speight, Jarrad Butler and Allan Alaalatoa re-signing.

It's understood Larkham's future was part of player negotiations. Some players pushed for answers on Larkham's future at the Brumbies before making their own decisions to stay in Canberra.

"There will be more responsibility, it will still be the role in being in charge of the backs and being in charge of the team," Larkham said.

"Maybe I'll have a bit more hand in defence and attack, but it will be fairly similar. We'll also bring someone in to fill the position Laurie had with the team."

Fisher's surprise exit shocked the players on Friday before their crucial game against the NSW Waratahs on Saturday night.

Fisher is a hands-on coach and has previously expressed his desire to return to Europe to coach in the forwards-dominated competition.

Fisher and Larkham's roles were split after the abrupt departure of head coach Jake White last year. The duo, who have previously worked together as player and coach, embraced the collaboration.

Shocked Brumbies players were called into a meeting on Friday morning to inform them of Fisher's decision.

"The guys were quite emotional [when Fisher quit], they all gave him 30 seconds of clapping when the team was informed, they gave him a hug and then we got on the bus to Sydney for [the Waratahs game]," Larkham said.

"Moving forward we'll be looking for a coach over the next couple of weeks or months and we'll do it as an organisation."

Fisher backed Larkham to be the Brumbies man in charge next year.

"He's prepared to put in the time, he's made great progress ... the hours and varying hours for a coach are a lot different to that of a player and [Larkham] has adapted really well," Fisher said.

"I think [the club] is in a really good place. The attitude and quality of the players and the program is superb."

Brumbies captain Ben Mowen, who will move to France at the end of the Super Rugby season, said the club was in a good position to move forward.

"It's the same as when we lost Jake, the next guy steps in and I've got no doubt that will be the same next year," Mowen said.