Listings of Hawai'i homes for sale or rent are headed for infinitely broader distribution into the global marketplace through a search tool being developed by the world's dominant Internet search engine, Google.

The tool, called Google Base, is a database containing real estate listings provided by the industry and made searchable and sortable through Google's standard search engine.

Google has been building the database nationally since last year, and as of Oct. 1 began receiving Hawai'i's mother lode of listings from the Honolulu Board of Realtors.

As the operator of O'ahu's Multiple Listing Service, the Honolulu Board of Realtors is the state's largest purveyor of residential real estate listings.

The trade association with about 6,000 members and 6,000 listings is uploading its listing data daily to Google for free, in return for the exposure featuring no advertising or sponsored links.

Prior to the board's MLS uploads, some independent agents and large real estate franchises were contributing local listings to Google.

But the Honolulu Board of Realtors is the only one of Hawai'i's three MLS providers supplying listings to Mountain View, Calif.-based Google Inc. The other two MLS systems, which cover real estate broker associations on Maui, the Big Island and Kaua'i, plan to do so.

National real estate listing consolidators have mushroomed in the last few years, with competitors such as www.realtor.com, www.trulia.com, www.zillow.com, www.yahoo.com, www.craigslist.org, www.realty.com and others. But some in the industry view Google's entry as a shot above a cluttered field of rivals.

"It's staggering — 80 percent of all (Internet) searches start on Google," said Beth Berry, marketing director for Hawaii Information Service, the MLS provider for Big Island and Kaua'i real estate associations. "That's where people are going. Obviously, we want to be represented there."

Berry said Hawaii Information plans to send data to Google Base, as does the Realtors Association of Maui.

Dan Tabori, executive vice president of business operations for Prudential Locations, said Google's real estate database is still relatively untested, so it will take time to see what kind of use the system develops between consumers and real estate agents.

"We just see the Google Base as another distribution channel," he said.

Prudential began uploading its listings in Google's database a few months ago, Tabori said.

Google claims that 56.5 percent of all Internet searches for "real estate" and related terms are made on Google and its partner sites.

But the company's home listing tool has yet to emerge into widespread consumer use because Google is still working to integrate its real estate listing database with general searches.

To illustrate the integration issue, anyone searching for "Honolulu real estate" or "Honolulu home for sale" on Google last week would find a special housing search box positioned above traditional results for real estate agent Web sites.

Through this housing search box, users are delivered to part of Google's database page (www.base.google.com) where more focused or expanded searches can be defined by a home's price, location, size, age or custom keywords such as farm or fireplace.

But access to the database through Google's main search window remains fairly narrow. The special home listing search-box portal appears in "real estate" searches for Wai'anae, Kane'ohe, Lihu'e and Wailuku — but not 'Ewa Beach, Waikiki, Mililani, Hilo, Ka'anapali, O'ahu, Hawai'i, Maui or Kaua'i. Once inside Google Base, however, searches by island, city, state or zip code are possible.

The same is true for many cities, states and places around the country.

Justin McCarthy, Google's strategic partner development manager focusing on real estate, said the company is working to improve search results as it refines the system and receives more listing data.

"Our ability to return results is not optimal yet," he said.

Google also said it is still ramping up its ability to upload listings. Last week, there were about 3,500 Hawai'i property listings in Google's database — far fewer than the 6,000 listings in the Honolulu Board of Realtors' MLS.

Another issue with Google's database is that it relies on submitted data, so the information is only as good as what providers send. So for instance, Google's housing database contains some commercial real estate listings, expired links and at least a few misleading listings.

There are also bugs in sorting data. For example, it's not uncommon to find Kane'ohe homes in a search for Kaua'i homes.

McCarthy said Google is still working to improve its system, and has a feature to report improper or incorrect items.

Google began planning its real estate listing database only about two years ago, after surveys revealed that many consumers were seeking, but not finding, real estate listings on Google.

According to a National Association of Realtors survey, 85 percent of home buyers used the Internet to search for a home last year, up from 77 percent in 2005.

Historically, a Google search for "Honolulu home for sale" returned links to Web sites of companies selling real estate as opposed to listings of homes for sale.

"There was this disconnect," McCarthy said. "Consumers were coming to us overwhelmingly looking for this information, and we weren't giving it to them."

Last year, Google began meeting with real estate industry leaders, including Hawai'i MLS providers, in an effort to obtain listing data.

To manage the data, Google created a system much like a free online classified ad system that is updated daily, searchable and sortable — and connected it to Google's main search engine. Google has also created similar databases for jobs, cars and other items.

Initially, there was much fear from MLS system operators and agents over how Google would use listing information, but Google allayed concerns held by much of the industry.

Late last year, the MLS operator in Houston became the nation's largest MLS to partner with Google. McCarthy said a couple of dozen MLS systems are submitting data to Google along with scores of agents and national franchise brokers.

Google stresses that its database is not a national MLS because listing information is abbreviated. By contrast, listing information available to real estate association member agents contains many more details, such as how long a home's been on the market and changes in list price.

Each data supplier decides how much information to include in their listing, though some MLS system operators consider certain details proprietary and tend to restrict what is made available to the public.

Still, listings on Google have several user-friendly attributes, such as thumbnail photos and home locations on a map. Also, each listing links back to an original listing either on a Web site of the seller's representative or MLS operator.

For Mary Beth San Juan, owner and principal broker of five-agent firm Happy Hawaii Homes LLC, the Google connection provides free exposure that she said she wouldn't have as a small independent operator with little time and money to direct Web users to her Internet site.

"I'm very happy with Google and what they provide," she said. "I was very impressed."

Rochelle Lee Gregson, Honolulu Board of Realtors' CEO, said the Google deal should leverage visits made to the board's Web site, www.hicentral.com, which averages 83,000 searches a month.

"This is one more way of promoting our Realtor members' listings," she said. "By providing our member listings to one of the world's most widely used search engines, their properties can now be viewed by a larger audience."

Reach Andrew Gomes at agomes@honoluluadvertiser.com.