April 6 (Bloomberg) -- Google Inc., the most-used Internet search engine, has successfully tested advertising on mobile phones in Japan, signaling a new revenue opportunity for the company.

``Mobile internet usage is fairly high'' in Japan, Deep Nishar, a Google product manager, said today in an interview at the CTIA Wireless 2006 trade show in Las Vegas. ``We've had a fairly successful trial of mobile text ads there.''

Google is adding more wireless phone services including Internet search and maps to attract consumers who need answers while on the move. Advertisers may be willing to pay more for cell-phone ads than for those shown on computers because mobile consumers may be closer to making a purchase, Nishar said.

Software that uses the geographic positioning features of cell phones will also be developed at Mountain View, California- based Google, Nishar said. That will let a user search for nearby businesses without specifying his own location.

Mobile phone users in the U.S. today can do searches on Google buy sending a text message to a special phone number. A message such as ``weather in San Francisco'' generates a reply message from Google with a weather forecast. Google's mobile mapping software displays the location of local businesses on maps and satellite images.

Infant U.S. Market

Nishar said Google isn't showing any ads on cell phones in the U.S. because the market is still in its infancy.

``We believe this is a phase when people should be investing in the market as opposed to trying to harvest something that isn't quite there yet,'' he said.

Google shares rose $3.19 to $411.18 at 4 p.m. New York time in Nasdaq Stock Market composite trading. They have more than doubled in the past year.

In May, Google bought Dodgeball.com, a Web site that allows mobile phone users to monitor the location of their friends.

In August, Google acquired Android Inc., a company headed by Andy Rubin, who was previously chief executive officer of Danger Inc., a Palo Alto, California-based company that makes Internet software for cell phones.

``I work in close partnership with the Android team,'' Nishar said. ``They also bring a lot of great experience in terms of the mobile domain in the U.S.''

To contact the reporters on this story: Jonathan Thaw in San Francisco at jthaw@bloomberg.net; Fred Fishkin in Las Vegas at ffishkin@bloomberg.net.

Last Updated: April 6, 2006 18:10 EDT