Compass, the real estate brokerage, claims that Zillow, the website that has 227 million unique visitors a month, has conspired to maintain a monopoly over digital home listings.

Compass, the real estate brokerage, claims that Zillow, the website that has 227 million unique visitors a month, has conspired to maintain a monopoly over digital home listings.

Compass is suing Zillow over what it calls the "Zillow ban," a new rule that the real estate brokerage firm claims is meant to control home listings and crush the home search…