The Australian Rugby Union announced its intention to axe the Perth-based Western Force side from Super Rugby on Friday but the protracted saga may not be over yet with Rugby Western Australia pondering a legal challenge to the decision.

The ARU said in April that they would cut either the Force or the Melbourne Rebels from Super Rugby next season as the competition contracted from 18 to 15 teams because of falling revenues and fan interest.

"Our decision to exit the Western Force has been guided primarily by financial outcomes," ARU chairman Cameron Clyne said in a statement.

"This is a sad day for rugby, especially for Western Force fans. We accept that there will be anger and resentment over this decision and we sympathise with those fans. We sincerely hope that they are not lost to the game forever."

RugbyWA responded almost immediately with a statement saying it would pursue "every possible means", including legal action, to ensure the Western Force remained in the competition.

"RugbyWA is considering all options including bringing urgent proceedings in the Supreme Court of (New South Wales), and legal action relating to the circumstances which led it to enter into the alliance agreement with the ARU," it read.

Billionaire mining magnate Andrew Forrest warned the ARU earlier this week that he would be first in line to fight the embattled governing body if it cut Western Force.

With Forrest throwing his weight behind the team, the battle over the future of the Force could still be dragged out in a long legal battle the cash-strapped ARU can ill afford.

The Force went to arbitration with the ARU last week arguing the alliance agreement they signed when they were bailed out by the ARU last year guaranteed them Super Rugby until the end of the current broadcasting deal in 2020.

The ARU contended that the contraction of the competition for next year effectively meant there was a new broadcast agreement in place for 2018.

Against a background of widespread dissatisfaction with the 18-team format, governing body SANZAAR earlier this year agreed to remove three teams from the competition.

South Africa have already culled the Cheetahs and Kings, who have both announced they will move to play in an expanded Pro14.

Leinster will play the first game of the competition in South Africa when they take on the Kings on 16 September in Nelson Mandela Bay Stadium. They face the Cheetahs in Bloemfontein's Toyota Stadium the following Friday.

Ulster will host the first South African side; they will play the Cheetahs on the opening night of the season, September 1.

The ARU quickly ruled out cutting previous Super Rugby champion teams the New South Wales Waratahs, ACT Brumbies and Queensland Reds, leaving a choice between the Force and Rebels.

Rebels owner Andrew Cox confirmed last weekend that he had transferred ownership to state governing body Victorian Rugby Union (VRU), declaring the move had "secured" the team's future.

The Force were an expansion team aimed at spreading the geographic imprint of rugby to the Australia's west coast when they joined the competition in 2006.

They have never reached the play-offs and the ARU gradually moved to the view that having five Super Rugby teams was stretching Australia's rugby resources too thinly.

The Rugby Union Players' Association (RUPA) said Friday was the "darkest day in the history of Australian rugby" with the ARU "abandoning the game's national footprint".

ARU chief executive Bill Pulver, who had already confirmed he would not seek reappointment when his contract expired next year, said he would now be leaving as soon as a replacement could be found.

"We're dealing with the process of cutting a Super Rugby team and that's been a harrowing process," he told a news conference.

"It's a good time for renewal and I think we need a fresh set of eyes."