Mozilla is switching the default search engine in its Firefox Internet browser from Google to Yahoo.
The change, which will only occur within the United States, was announced by Yahoo CEO Marissa Mayer on a post in Yahoo's official Tumblr page.
Yahoo and Mozilla signed up for a five-year partnership, which Mayer said is the company's most significant in five years.
Firefox users in the United States will see the change in December.
Another part of the agreement between the companies will have Yahoo support Firefox's Do Not Track feature, which prevents the online activity of users from being tracked for advertising uses.
Firefox, which has a user base of millions that make 100 billion searches yearly, is one of the major sources of Google's search traffic. Some of the searches lead to search ads, which is one of the primary funding sources of Mozilla as Google shares part of the revenue to the company.
However, with the launch of Chrome, Google has a browser that doesn't require it to share its revenue from search ads with another company.
This is where Yahoo comes in, as the company looks to reclaim its lost dominance of online search.
"This partnership helps to expand our reach in search and gives us an opportunity to work even more closely with Mozilla to find ways to innovate in search, communications, and digital content," Mayer said.
Mozilla's decision to move away from Google and towards Yahoo is partially spurred by the regional flexibility that a partnership with Yahoo provides. However, another factor that motivated the deal was Mozilla's mission for search experience improvement for the users of Firefox.
"They're open to innovations," said Mitchell Baker, the chairwoman for Mozilla. The innovations include further development on the "awesomebar" of Firefox, which is able to make searches through both online and for the content already on the user's device.
Baker added that the negotiations with Yahoo were much simpler compared to those with Google, which is now in direct competition with Mozilla with its attempts to lure users away from Firefox and into Chrome.
Once the change occurs, Firefox users will still be able to change their browser's default search engine as they wish. However, according to Jackdaw Research chief analyst Jan Dawson, many Firefox users might not bother changing their default search engine back to Google.
"Google should be concerned," Dawson said. "This could mean a significant switch in market share away from Google toward Yahoo."
