Agency shareholders of OnTheMarket will vote whether to accept a takeover approach from CoStar UK on 4 December.
CoStar, owner of US portals Homes.com and Apartments.com, has made a £100m takeover bid through its UK arm for OTM and vowed to “aggressively” build the business and grow its market share.
The offer is worth 110p per share for OTM.
OnTheMarket has urged its shareholders to back the offer and needs 75% of backing for the deal to go through.
It has already had support from around 30% of its shareholder base.
Agents have until 30 November to send in any proxy votes and if the deal is backed at the meeting on the 4 December, the takeover could be finalised a week later.