Compass’ lawsuit against Zillow highlights the growing power struggle in online real estate

Two of the nation’s real estate titans are on a collision course.

Compass, one of the largest brokerages in the country, has filed a complaint in a New York federal court against Zillow, alleging the online behemoth is engaging in “anticompetitive tactics” and violating antitrust laws.

The suit accuses Zillow of banning listings that were marketed elsewhere first, saying it has “retaliated against competitive threats by enacting an exclusionary policy.”

“This lawsuit...