OnTheMarket has announced that it is now listing some 550,000 sales and rental properties – over half the total number available.

It says it has two-thirds the number that Zoopla has and over half those carried by Rightmove.

As at July 3, Zoopla had 580,860 UK residential sales properties and 241,390 UK residential lettings properties, totalling 822,250 properties.

Rightmove is assumed to have about 1m properties – the number it gave in both its 2016 and 2017 annual reports.

The figures for both Zoopla and Rightmove include direct listings from new home developers, a market segment which OTM is yet to focus on.

The increase in listings at OTM reflects the rapid growth in contracted agents with agreements to list their properties on the portal.

As at July 3, the number of contracted agent offices has grown, since the admission to AIM on February 9, from 5,500 to more than 9,500, which represents an increase of more than 72%. The company said it believes that it has listing agreements with approximately 51% of UK residential estate and lettings agency branches.

CEO Ian Springett said: “We are extremely pleased that, as a result of our reported growth in contracted agents, OTM is now displaying well over half of the market in terms of UK residential properties.

“The very strong and growing agent support for our proposition has enabled us to rapidly gain ground on the market share of property listings of our long-established key competitors.

“We remain committed to creating an agent-backed, full-scale challenger portal that injects some much-needed competition into the property portals landscape by disrupting what has for too long been effectively a cosy duopoly.”

Yesterday, shares in OTM closed at 162.5p, up 2.85% on the day but below the 165p they were offered to the market at launch on AIM.