A9.com Inc on Thursday launched a yellow-page service that provides a street-level view of buildings on either side of a listing, giving the subsidiary of giant retailer Amazon.com Inc. a leg up on local search offered by Google Inc., Microsoft Corp. and Yahoo Inc.

The Palo Alto, Calif., company's new "Block View" technology let's users take a virtual walk to the left or right of a business to see what restaurants, shops or offices are located in the immediate area. A listing for Brendan Lai's Martial Arts Supply Co. in San Francisco's Mission District, for example, included images that showed not only other businesses, but also a Bank of America ATM machine and a station for the city's BART subway.

Along with the images, a user can get a street map and directions to a listing, and can click on a button to place a telephone call to the business. The service currently covers more than 10 U.S. cities and has more than 20 million photographs.

Businesses listed are not charged, and can add promotions, images, links or other information through A9.com's web-based tools, Udi Manber, chief executive for A9.com, said. They cannot change content in listings.

Manber declined to discuss how A9.com would make money from the new service, nor would he discuss marketing plans or whether the company would license use of its local images and content. A9.com has done very little marketing, so remains far less known to the average consumer than its three major competitors.

Despite the expense of developing and launching the new service, A9.com didn't do any research to determine whether including images in a yellow-page listing would make consumers more likely to buy from the business.

"This is not something that grew out of focus groups or market research," Manber said. "We're not doing any marketing. We're relying on word of mouth."

The technology was added because it's "very innovative," he said. "We try to break new ground and do things differently."

Block View is unique among local search engines in the U.S., Gary Price, analyst for SearchEngineWatch.com, said. A similar service has been available for a while on France Telecom's Yellow Pages site, Pages Jaunes.

"For a start, it's incredibly cool," Price said of the A9.com service. "It's a completely unique service in the U.S."

As to potential financial benefits for A9.com, the service's content and technology could be licensed to other businesses, such as local yellow-page directories, and it could draw more traffic to the search engine and Amazon.com, which has an A9.com link on its home page.

Manber declined to disclose traffic figures, but said both sites do send traffic to each other.

To gather the images along city streets, A9.com has hired people to drive trucks with digital video cameras mounted on top. The trucks are connected to a global positioning system, and software developed by A9.com is used to gather and organize the content.

Although A9.com drivers have crossed 10s of thousands of miles to gather images, the service does not appear to cover suburban areas even around the cities listed.

A9.com, however, is continuing to expand the service. "We're driving right now, so they'll be more cities added," Manber said.

Among the top three search engines of Google, Yahoo and Microsoft, Yahoo has made the most gains against its rivals through local search, according to a survey of 2,000 web users by research firm Keynote Systems Inc.

Over the last six months, Yahoo has made significant improvements, including the addition of traffic information to its online local map service.

Local search holds strong revenue potential for search engines, since many web surfers look for products and services near their home or in cities they're visiting. In general, however, local search draws the most complaints from consumers, who often find that the results don't match their needs, Keynote has found.