Yahoo has won one back from Google: It will replace Google's search engine on Firefox's Web browser in the US - a notable coup for Yahoo chief executive Marissa Mayer, a former Google executive.
Observers took it as a marker of Yahoo's resolve to get back some of the ground that it has lost in the most lucrative part of the Internet's ad market, said the San Jose Mercury News.
The five-year alliance will end a decade-old partnership in the U.S. between Google and the Mozilla Foundation, which oversees the Firefox browser.
Tensions between Google and Mozilla had been rising since Google's introduction of the Chrome browser in 2008 began to undercut Firefox. Google's current contract with Mozilla expires at the end of this month, giving Yahoo its chance.
Chrome is now more widely used but Firefox still has a loyal audience that makes more than 100 billion worldwide search requests annually.Yahoo is hoping to impress Firefox users , showing it's still good at Internet search after leaning on Microsoft's technology for most of the results on Yahoo's own website for the past four years
Financial details weren't disclosed. In a blog post, Mozilla chief executive Chris Beard said the new deal offers "strong, improved economic terms" while allowing Mozilla "to innovate and advance our mission in ways that best serve our users and the Web."
Google accounted for 90 percent, or about $274m, of Mozilla's royalty revenue in 2012. Besides dropping Google in the U.S., Mozilla is also shifting Firefox to Baidu's search engine in China and Yandex in Russia.
Firefox users can still pull down a tab to pick Google and other search engines as their preferred way for looking up information online.
Marissa Mayer hailed the Firefox agreement as Yahoo's most significant partnership since forging the Microsoft deal in 2009.
"We believe deeply in search -- it's an area of investment and opportunity for us," Mayer wrote in a Wednesday blog post.
Yahoo plans to unveil a "clean and modern" search engine on Firefox next month and then roll out the new model on its own website early next year, Mayer wrote.
The redesign will primarily affect how Yahoo's search engine's results are displayed, and not the way that requests are processed. The search technology will continue to be provided by Microsoft as part of a 10-year deal Yahoo signed in 2009, according to Mel Guymon, Yahoo's vice president of search.
