OnTheMarket has recruited two sister firms with 28 branches between them.
One is Townends, a 21-branch estate and letting agency firm covering London, Surrey, Middlesex and north Hampshire, and the other is London business Stirling Ackroyd, with seven branches.
Both businesses are owned by Nick Dunning Associates.
Matt Hewitt, commercial director at Nick Dunning Associates, which is run by a team of ex-Countrywide seniors, said: “In an increasingly digital world it is important to be represented on all the major portals and OnTheMarket has shown itself to be gaining momentum and becoming a credible challenger to the big two.”
OTM announced on August 23 that 10,500 agent offices were in contract with the portal, believed to be approximately 57% of UK residential estate and letting agency branches.