A group of homebuyers told a Pennsylvania federal judge that brokerage Hanna Holdings failed to show cause for escaping antitrust claims over its use of rules set by the National Association of Realtors that artificially drove up the cost of house purchases.

A prospective class of homebuyers said Monday that the court had already considered and tossed many of the brokerage's arguments in June, when a federal judge reviewed nearly a hundred pages of briefing and heard two oral arguments and decided to keep some claims against Hanna alive.

After the homebuyers filed an amended complaint in the case in October, Hanna moved to dismiss the latest version of the arguments.

Hanna is the largest privately held brokerage in the country. U.S. District Judge Wendy Beetlestone in June found the brokerage's relationship with NAR could be considered a vertical structure that could indicate a violation of antitrust laws.

"Hanna's oversize motion reads like none of that ever happened," the homebuyers said. "Its bid to relitigate the many issues it has already lost should be rejected."

The September 2024 lawsuit from the homebuyers in Pennsylvania federal court followed a 2023 decision by a jury in Missouri federal court that found NAR's commission structure drove up costs for home sellers by requiring them to pay the broker fees of homebuyers. North Carolina resident Scott Davis is leading claims from plaintiffs in the Pennsylvania case.

Homebuyers in the lawsuit argue they are harmed by NAR rules that steer buyers to homes with higher broker commission rates and away from homes that pay brokers lower rates.

Additionally, the preferences of buyers are given less priority when buyer-brokers steer homebuyers toward certain properties based on commission rates, according to the lawsuit.

The suit claims Hanna executives sit on NAR boards and that the firm requires its franchisees and brokers to follow rules set by the trade group. Hanna also extends NAR's policies to any broker using the MLS online home listing service.

In the June decision, Judge Beetlestone rejected arguments from the homebuyers that the relationship between Hanna and NAR amounted to a horizontal arrangement that's inherently illegal under antitrust law.

The ruling, however, also rejected claims from Hanna that the market for homes at-issue was too expansive to establish a vertical conspiracy that could amount to an antitrust violation. Judge Beetlestone found the homebuyers met a standard of pleading that the market in the case covers an area where a buyer might reasonably shop for homes.

On Monday, the homebuyers pushed back against Hanna's arguments that a vertical conspiracy doesn't exist with NAR based on the Ninth Circuit's August decision in Gibson v. Cendyn Group .

The Gibson ruling rejected arguments of a vertical conspiracy to fix hotel room prices because a software provider supplied a different product to different customers. The homebuyers argued that the NAR, by contrast, dictates the behavior of any broker using the MLS.

Meanwhile, the homebuyers argued Monday that their amended complaint alleged a plausible horizontal conspiracy between Hanna and NAR that's inherently illegal. They said they'd met the tougher standard for such a claim by arguing that NAR's rules effectively amount to an agreement with brokerages.

Even without direct evidence of such a horizontal arrangement, circumstantial evidence points to such a relationship between Hanna and NAR, the buyers claimed.

"Defendants were motivated to conspire to keep their commissions high and buyer-brokers relevant as the internet threatened to usurp the role of buyer-brokers They had numerous opportunities to collude through industry associations and meetings – in an industry that had been repeatedly investigated for anticompetitive conduct."

Counsel for the parties did not immediately respond to messages seeking comment Tuesday.

Hanna Holdings is represented by Eric G. Soller and William Pietragallo II of Pietragallo Gordon Alfano Bosick & Raspanti LLP and Claire Bergeron, David Z. Gringer, Emily Barnet, Jackson Frazier, Jane Kessner and Seth P. Waxman of WilmerHale.

The plaintiffs are represented by Peter Demato, Christian Levis, Margaret C. MacLean, Noelle Forde, Vincent Briganti and Anthony M. Christina of Lowey Dannenberg PC and Carol O'Keefe, George A. Zelcs, Michael E. Klenov, Randall P. Ewing Jr., Ryan Z. Cortazar and Steven M. Berezney of Korein Tillery LLC.

The case is Davis v. Hanna Holdings, case number 2:24-cv-02374-WB, in the U.S. District Court of the Eastern District of Pennsylvania.