CoStar Nudged Out of Joining Zillow Home-Listing Antitrust Suit

A federal judge denied CoStar Group Inc.'s motion to participate in a lawsuit opposing Zillow Group Inc.'s request for a preliminary injunction that would force a real estate data provider in Chicago to provide it with access to home listings feeds.

CoStar’s motion to file an amicus curiae brief was rejected Tuesday by Judge John J. Tharp Jr. of the US District Court for the Northern District of Illinois, who didn’t provide a reason.

CoStar wanted to argue that granting the request would reward Zillow’s allegedly anticompetitive conduct and allow it to retain the right to block “pre-market” private listings ...