T
he antitrust lawsuit filed by Compass against Northwest MLS (NWMLS) has sparked a lot of discussion, but it's not the first time a brokerage has sued an MLS over alleged antitrust issues. A notable example is the 2006 Federal Trade Commission (FTC) case against Michigan-based MLS Realcomp II.

    In that case, Realcomp II adopted a rule in 2001 limiting listings to properties listed on exclusive right-to-sell agreements. This meant that listings using exclusive agency agreements were not transmitted to approved real estate websites, including Realtor.com and Moveinmichigan.com. Home Quarters Real Estate and Eugene Allan claimed they were harmed by this policy, which prevented discount brokerages from competing in the marketplace.

    The FTC ultimately found that Realcomp's policy stifled competition, leading to a settlement requiring the MLS to provide non-discriminatory access to non-traditional listings. Fast forward to 2025, Compass is suing NWMLS for allegedly stifling competition by not allowing it to fully utilize its business model. Unlike Home Quarters, Compass operates as a traditional brokerage.

    Compass claims that NWMLS's listing policy, which doesn't allow office exclusives like the National Association of Realtors' Clear Cooperation Policy (CCP), harms consumers and competitors. To win its Sherman Antitrust Act claim, Compass must prove that NWMLS is a monopoly and engaging in exclusionary conduct that harms competition.

    Paul Rogers, an antitrust law professor at Southern Methodist University's Dedman School of Law, notes that Compass will need to show that the rules harming consumers also harm competition. This echoes the FTC's findings in its case against Realcomp II.

    Compass CEO Robert Reffkin has also accused Zillow of engaging in anticompetitive behavior by banning listings not entered into the MLS. Reffkin drew parallels between Zillow and Google, citing the latter's dominance in search advertising. However, Rogers notes that if a suit were to arise, Compass would still need to prove that consumers are harmed by Zillow's actions as a monopoly power.

    As the battle over CCP becomes more litigious, it's possible that the Department of Justice (DOJ) may get involved. Steve Murray, co-founder of RealTrends Consulting, believes the DOJ is more likely to take action than the FTC, which focuses on consumer harm. Attorney Rob Hahn also thinks the DOJ might intervene in the Compass v. NWMLS case, citing a recent statement by the Antitrust Division's second-in-command that views the lack of competition for listing services as a problem.