The Arizona Regional Multiple Listing Service is one of six major MLSs to join a new lawsuit against Compass.

ARMLS, bridgeMLS, Canopy MLS, Doorify MLS, Hive MLS and REcolorado filed a joint complaint with the United States District Court in New York’s Southern District, alleging that Compass policies give the brokerage an unfair advantage by withholding properties from the public.

Compass previously threatened lawsuits against the MLSs unless they stopped enforcing rules requiring all listings to be publicly marketed and shared with all participating listing databases.

The complaint from the six MLSs is asking the court to find that each organization’s rules abide by federal and state antitrust laws — namely Section 1 of the Sherman Act — and to prevent Compass from pursuing further legal action pertaining to the case.

“Arizona’s real estate market thrives when every agent and brokerage has a fair opportunity to compete, regardless of their size or resources,” ARMLS CEO Matt Consalvo said in a press release. “From Phoenix and Scottsdale to communities across the state, our subscribers depend on a shared marketplace that gives them access to the same publicly marketed listings. We are taking this action to defend the corporation that allows agents to compete on their expertise and service, rather than who controls access to homes for sale.”