Agents' Mutual was last week ordered to make a further payment into court as part of its ongoing legal case against Gascoigne Halman and Moginie James.
Earlier this summer, the Financial Times revealed the parent company of the OnTheMarket portal was ordered to pay £1 million into court by the end of August.
The portal accuses the estate agencies of breaking the terms of their contracts by not adhering to its 'one other portal only' rule and listing properties on multiple portals.
In July, the cases against the agents were referred to the Competition Appeal Tribunal by the High Court.
Agents' Mutual's cases against Gascoigne Halman and Moginie James are due to be heard by the Competition Appeal Tribunal between February 3 and 20 next year, with a pre-trial review scheduled for December 15.
Gascoigne Halman, which is a Gold member of OnTheMarket, was acquired by the Connells Group in October 2015.
Agents' Mutual says it is standard procedure to provide security for costs in such cases and that it has taken appropriate legal advice.
The organisation reiterates that the funds would only be payable in the event that it was unsuccessful in its cases against the agencies.
It says it is taking appropriate action to ensure agents meet their contractual obligations and to challenge the allegation of misrepresentation in relation to its pricing policy.
Gascoigne Halman released a statement over the weekend, which reads as follows:
“Gascoigne Halman notes that the Competition Appeal Tribunal last week ordered Agents’ Mutual to make a further payment into Court of £830k to cover its legal costs in the event that Gascoigne Halman succeeds in the legal action being taken against it by Agents’ Mutual.”
“This, together with an additional £450k also ordered to be paid into Court in respect of a separate but related action, means that Agents’ Mutual will have paid into Court over £2m by year end.
“Agents’ Mutual also stated to the Court that their own legal costs will exceed £2m.”
“Gascoigne Halman is committed to defending its position and is confident that the Competition Appeal Tribunal will uphold its right to advertise on portals of its choice.”
“As a Gold member of OnTheMarket, Gascoigne Halman is extremely disappointed that Agents’ Mutual has chosen to divert over £4m of its members’ loan notes and subscriptions away from its marketing activities when they would surely be better employed for the benefits of its members.”