Wellington Phoenix have dragged Football Federation Australia to court over a contract dispute, though a settlement is expected within days.

New Zealand's sole A-League club and the league's governing body are listed to appear next Tuesday in the NSW Supreme Court's equity division.

Wellington's ownership consortium has filed documents with the court outlining their claim but they will not be publicly released until FFA has formally submitted its reply.

The court determines disputes valued at more than $750,000.

Sources have told AAP the matter is subject to ongoing negotiations, with the matter likely to be resolved out of court in the coming days.

Both FFA and Wellington have declined to speak publicly about the dispute or confirm the subject of their conflict.

Previous reports suggest it may be linked to audience metrics.

Last year, the Sydney Morning Herald reported FFA sent the Phoenix a bill for almost $1 million as Wellington didn't meet benchmarks prescribed in their previous licence agreement.

Wellington's stay in the competition was extended by four years in 2016, conditional on an increase in attendance and television ratings.

At the time the Phoenix were struggling to make their impact on the league, winning two wooden spoons in their opening eight seasons.

They've enjoyed better fortunes in the past two seasons, reaching the finals both years and igniting the professional careers of young Australian coaches Mark Rudan and Ufuk Talay.

Still, the Nix have reportedly failed to reach those benchmarks, prompting the contractual brouhaha.

A spokesman for the Phoenix denied the court listing related to the metrics issue.

There are still vast uncertainties surrounding the A-League, which has yet to fixture the upcoming season due to COVID-19.

The players union and league have been locked in a dispute over player payments though the parties are closing on a new collective bargaining agreement.

The league's broadcasting agreement with Fox Sports is also entering its final season after it was renegotiated earlier this year.

Wellington and its ownership remain committed to the A-League, with Welnix chairman Rob Morrison enjoying the support of other league chairmen to stay in the competition.