Yahoo To Offer A Network For Web Ads On Cellphones

SAN FRANCISCO, March 26 -- Yahoo is moving to secure a position on the next Internet battleground: Web search and advertising on cellphones.

The company plans to announce on Tuesday that it is creating a mobile advertising network that will allow marketers to place ads not only on its mobile services, but also on those of other online publishers. And Yahoo is offering tools to help publishers customize their content for easier use with its mobile search service.

Yahoo's network of publishers at this point is tiny -- three Web services, including MobiTV, a video service to be used with cellphones; Opera, a maker of Web browsers; and Go2, a Yellow Pages site. But the company said it planned to expand the network quickly over the next few months.

"We are being very aggressive on mobile and moving extremely fast to get the building blocks in place," said Steve Boom, Yahoo's senior vice president for broadband and mobile. "We felt that business services for publishers is something that was lacking."

Yahoo, which has fallen a distant second behind Google in Internet search and search-related advertising, has been busy promoting new mobile search software, which it introduced in January. The software, called oneSearch, is intended to allow users to quickly find information like sports scores and weather reports without scrolling through a long list of Web links.

"One area where Google has not outshined Yahoo is mobile search," said Kevin Heisler, an analyst at Jupiter Research.

By focusing on publishers and advertisers, Yahoo is courting groups that are essential to its success on the mobile Internet. The company hopes to start delivering text, display and video ads on third-party mobile Web sites by the summer, Mr. Boom said. It announced in February that it would deliver graphical ads on its own mobile Web service.

Advertising on sites arrayed for mobile phones is a tiny