Yahoo dialed up its mobile strategy Tuesday by launching a suite of search, social and content tools for Apple’s iPhone, Research in Motion’s Blackberry and other smartphones.

The applications, whose beta launch was announced at the Mobile World Congress in Barcelona, also will run on phones powered by Microsoft’s Windows Mobile and those made by Nokia, Samsung, Sony Ericsson and Motorola. A public launch is expected in late May, the company said.

Yahoo’s shares fell $.79, or 6.2 percent, to $12.05 in afternoon trading.

At the center of Yahoo Mobile is the company’s OneConnect, designed to pull together messages (e-mails, IMs, etc.) from social networks like Facebook and media-sharing sites like Flickr.

"We believe the new Yahoo! Mobile will transform the way millions of mobile users around the world will interact with the Internet," Marco Boerries, Yahoo executive vice president, said in a statement. "Yahoo! Mobile will enable users to create their own Internet starting point on their mobile device so they can better discover, connect to and stay informed about the people and things that are important to them."

Interest in smartphones as an advertising vehicle has surged in parallel with the increased market share of the iPhone and Blackberry models. Research Strategy Analytics reported that mobile handset shipments in North America fell 15 percent in the fourth quarter of 2008 versus the prior year. But while Motorola remained No. 1 in 2008, “above-average growth in smartphones” enabled Blackberry to double its market share versus the previous year’s period.