In a move that has raised eyebrows among established players in the classified real-estate business, Google Australia has unveiled a new tool on its mapping service that will directly link buyers and renters to available property.

The Google Maps feature, which launched today in Australia and New Zealand, will host free listings supplied by real-estate agents and publishers.

Although many existing publishers and real-estate agents offer map-based searching, the maps on Google's new service will reflect real-time changes in search criteria and location.

The technology behind this enhancement was developed by engineers at Google's Sydney office and is also being rolled out on the company's existing property search service in the United States.

Google's offering is open to all comers, potentially giving renters and buyers a much bigger choice.

But this development is likely to be viewed by existing publishers as a grab for their business at a time when margins are under pressure and paid listings are being affected by the prevailing economic climate.

The service is launching with listings provided by the Real Estate Institute of Western Australia and homehound.com.au, the free property listing service owned by Michael Hannan's Independent Print Media Group.

The two leading Australian online advertising portals are realestate.com.au, which is 60 per cent owned by News Corp, and domain.com.au, which is owned by Fairfax Media, publisher of this website.

John Brand, general manager, key categories, at Fairfax Media said domain.com.au would not at this stage be taking up the Google offer to contribute listings to the new service.

"We are quite confident that we provide a better service than Google is offering," he said in a telephone interview. "We are a specialist property portal and we think this will stand us in good stead going forward."

Google product manager Andrew Foster said the decision to launch the new service was driven in part by research showing that, increasingly, more people were using the internet to search for a home to buy or rent.

"And there's also been a 35 per cent growth in real-estate-related queries on Google in the year to Febraury 2009," he said.