In a deal that ends concerns that Mozilla would lose its primary source of revenue, Mozilla and Google have signed a new agreement that will lock in Google's role as Firefox's default search engine for at least three more years. "We’re pleased to announce that we have negotiated a significant and mutually beneficial revenue agreement with Google," Mozilla said in an announcement today. "This new agreement extends our long term search relationship with Google for at least three additional years."

ZDNet's Ed Bott noted earlier this month that the search deal was providing 84 percent of Mozilla's revenue, but appeared to expire at the end of November with no official statement from the companies involved. This sparked some concern about Firefox's future, given that it has already slid in market share compared to the fast-rising Google Chrome.

Mozilla put those fears to rest today, although specific financial terms of the deal are not being disclosed. While Mozilla CEO Gary Kovacs said Google "will continue to be the default search provider" in Firefox, Mozilla also recently unveiled a custom version featuring Microsoft's Bing. Mozilla is in a unique position, relying on its biggest rivals for revenue, and it's trying to maintain relevance with a more rapid release schedule, with the beta version of Firefox 9 available now.