Google (NSDQ: GOOG) is expanding its real estate listings on Google Maps in a move that could pit it against existing listing sites and could also create additional tension with listing services. Starting Monday, users in Australia and New Zealand can search for available properties on Google Maps, according to the Google Australia blog. Two listing services in Australia are contributing the initial listings. A third group said it would not provide listings, telling Australian newspaper The Age, “We are quite confident that we provide a better service than Google is offering.”

The existing real estate search on Google Maps in the United States has also been updated, according to SearchEngineLand, with an “updated and more comprehensive” version of the listings that previously were on the site as well as a new search box that allows users to search by square footage and whether a property is in foreclosure or not.

Google product manager Andrew Foster tells The Age that Google introduced the feature in Australia because more people were going online to look for real estate listings. “There’s also been a 35 per cent growth in real-estate-related queries on Google in the year to February 2009,” he says. Listing sites Trulia and Zillow have also seen significant increases in their traffic since the start of the year, according to Compete.com.

SearchEnglineLand notes that Google’s move to beef up its real estate listing search isn’t likely to win it many friends at the National Association of Realtors, which oversees listing services in the United States, has told some of its members to stop letting their listings be indexed by Google because the site is a “scraper.” But on the Understanding Google Maps and Local blog says that while Google may be expanding the service abroad, in the U.S., at least, it’s mostly just a “change in real estate presentation.”