Fairfax Media understands Castle has edged out former Wallabies captain Phil Kearns for the position, despite reports suggesting he was favourite to take over rugby's top job.

An announcement is expected to come on Tuesday that Castle will take over from incumbent chief executive Bill Pulver.

The appointment of the former Canterbury Bulldogs chief executive is a watershed moment for Australian sport given no female has ever been the boss of a major football code.

Rugby Australia - formerly the Australian Rugby Union - has had a tumultuous year off the field and its rebrand in late October shows the organisation is keen to move in a fresh direction.

There was an appetite within Rugby Australia ranks for the new chief executive to be a "rugby person" but Castle's expected appointment shows the code wants a fresh set of eyes to put it on a new path.

On the same day Rugby Australia confirmed it was set to cut the Western Force from next season's Super Rugby competition, Pulver announced he would not continue on as chief executive.

More than a hundred people applied for Pulver's job and in recent weeks that number was cut to only three.

It is understood Castle has expressed a desire to one day become the boss of New Zealand Rugby but her newest role shows she is keen to come in and shake things up in Australia.

Castle is a well-respected administrator and was the first female boss of an NRL club before resigning in May. She ended her role at Canterbury at the end of the season.

The former New Zealand netball boss was one of the most influential figures in rugby league and there will be plenty of interest to see how she fares in her new position.

Plenty of people in rugby circles were keen for Kearns to take the code's top job but it is understood Castle has edged him out in a significant and potentially code-defining decision.

In recent years rugby has tried to shake its image of being a male-dominated sport played predominantly at private schools.

Australian rugby is a complex beast and Castle will have to quickly get up to speed with the politics that have sometimes tainted the code in recent years.

Clearly those who appointed the New Zealander believe she can adopt an understanding of how rugby operates from grassroots to the professional level.

In the meantime, it has been reported Castle will sit on a two-person panel that will review the New Zealand rugby league team's premature exit from the recent World Cup.