Hamilton real estate agency Online Realty is the latest company to be fined for price fixing, and has been ordered to pay more than $1 million.
The firm, which is part of the Ray White stable, has been ordered to pay a penalty of $1.05m by the High Court.
A total of 13 national and regional real estate agencies were accused by the Commerce Commission of entering into anti-competitive agreements in response to Trade Me changing its property listing fee.
The others included companies like Barfoot & Thompson, Harcourts, LJ Hooker, Ray White and Bayleys.
To date, the case has seen almost $19 million in court-imposed penalties.
Further court action is set for September.
The Commerce Commission case said the companies agreed to pass on the cost of listing on Trade Me to vendors, after the online auction site changed its listing fee from a monthly subscription to a per-listing fee.
In her judgment, released yesterday, Justice Patricia Courtney said while Online Realty was not a ringleader in the case, the conduct had brought a significant and lasting change to the market, with the majority of Hamilton real estate agents continuing to pass on the cost.
The Commerce Commission proceedings began in December 2015.