A NEW fight has broken out between two of the country’s biggest real estate companies over how home listings are shared online.

Compass has taken Zillow to court, accusing the real estate platform of blocking listings in a way that shuts out competition.

The lawsuit was filed after a new Zillow rule kicked in on May 28.

Compass has claimed in its filing that Zillow is breaching antitrust laws by prohibiting any home listing from being on its site if it shows up elsewhere more than 24 hours before it’s on its platform.

The change was announced by the company in April 2025 and took effect late last month.

According to Zillow, the rule ensures fair access to listings for all buyers, not just those working with select brokerages.

But Compass claims the policy violates federal antitrust laws and was designed to thwart rival firms.

The company says Zillow has used its market power to block listings that appear first elsewhere, CBS News reported.

“This lawsuit is about protecting consumer choice,” Compass CEO Robert Reffkin said in a statement.

“No one company should have the power to ban agents or listings simply because they don’t follow that company’s business model.”

“That’s not competition. It’s coercion,” Reffkin added.

“Imagine if Amazon banned a seller for offering a product on their own website first.”

“That’s what Zillow is doing in real estate. Consumers should have the right to choose how they sell their homes.”

Compass said it has tapped top antitrust lawyer Ken Dintzer to represent it in the case.

Dintzer previously led the US government’s antitrust case against Google.

Zillow hit back, saying the lawsuit is baseless and it plans to fight it.

“Compass’ claims are unfounded,” the company said in a statement to CBS MoneyWatch.

“The core of this matter is a straightforward idea: Once a listing is marketed publicly, it ought to be available to all buyers across every platform, including Zillow.”

The company warned that hiding listings creates a broken market and hurts buyers, sellers, and the entire industry.

The lawsuit highlights Compass’ three-step listing strategy, which it says helps sellers get more exposure.

First, homes are shared privately within Compass’ internal network.

Next, they’re listed as “coming soon” on Compass’ public site.

Only after that do listings move to public databases like MLS and aggregation sites like Zillow.

Compass says this phased rollout gives sellers more control and helps agents match homes with serious buyers early on.

But the company has argued that Zillow’s new rule blocks that system, especially in the early stages.

“For Zillow, every home buyer search conducted on Compass instead of Zillow is a lost opportunity,” the lawsuit states.

The complaint claims Zillow wants to drive all traffic to its site to sell buyer information to agents for a fee.

It also says Zillow can’t profit from Compass’ private or early-stage listings because they don’t appear on its platform.

Compass, which has over 33,000 agents, said nearly half its sellers used the three-step process in the first quarter of 2024.

“In a marketplace that is free and competitive, the products and strategies of competitors should succeed or fail based on their own merits, rather than the arbitrary control of a monopolistic gatekeeper like Zillow,” the company stated in the complaint.

Zillow and Compass didn’t immediately respond to a request for comment by The U.S. Sun.