CoStar asks US Supreme Court to hear real estate antitrust case

CoStar

10/12/2025 15:44

By Mike Scarcella

WASHINGTON, Dec 10 (Reuters) - CoStar Group CSGP.O has asked the U.S. Supreme Court to take up its dispute with a rival real estate data provider, warning that a recent federal appeals court ruling could chill innovation and spur costly litigation.

CoStar told the justices on Monday that the San Francisco-based 9th U.S. Circuit Court of Appeals improperly ruled in June to reinstate antitrust allegations by rival Commercial Real Estate Exchange Inc (CREXi). The appeals court reversed a lower court's order that had dismissed CREXi’s claims.

CREXi claims CoStar violated antitrust law by locking real estate brokers into using its data platforms and blocking rivals from accessing key web tools.

CoStar has denied any wrongdoing, saying it has no obligation to provide competitors access to its websites and databases. CoStar general counsel Gene Boxer in a statement on Tuesday said the allegations “were concocted in order to manufacture leverage after CREXi was caught red-handed engaging in mass infringement.”

CREXi in a statement called the Supreme Court petition “just another attempt by CoStar to delay its inevitable liability for years of anticompetitive misconduct against the commercial real estate industry.”

California-based CREXi made its antitrust allegations as counterclaims against CoStar in a copyright lawsuit that CoStar lodged against the rival in 2020.

CoStar’s ongoing lawsuit accuses CREXi of deliberately copying tens of thousands of CoStar photos of real estate properties in what it has described as an international “industrial-scale” copyright infringement scheme.

In its filing at the Supreme Court, CoStar said the 9th Circuit broke new ground by allowing an antitrust claim to proceed even though its contracts are expressly nonexclusive.

CoStar also said a prior Supreme Court decision generally allows companies to refuse to deal with competitors.

CoStar said the 9th Circuit order, if left in place, would deter companies from investing in proprietary tools if courts can force firms to share those assets with rivals.

The case is CoStar Group Inc v. Commercial Real Estate Exchange Inc., U.S. Supreme Court, No. 25-667.

For CoStar: Melissa Arbus Sherry of Latham & Watkins

For CREXi: No appearance yet

Read more:

US judge dismisses nationwide renters' lawsuit over mobile home lots

Airbnb sues Mississippi city over short-term rental restrictions

US states sue Zillow, Redfin over rental listings

CoStar, luxury hotels defeat room rental price gouging lawsuit

Zillow sued by Homes.com owner CoStar for 'massive' copyright violations

(Reporting by Mike Scarcella)

((Email: mike.scarcella@thomsonreuters.com; Phone: 202-985-8228.))