"This agreement now ends in November of 2011 rather than November of 2008, so we have stability in income," said Mitchell Baker, currently the chairwoman of Mozilla.
Mozilla generates the bulk of its income from ties to Google, according to the company's latest financial results. For the 2006 tax year - the most recent numbers make public by Mozilla - 85 percent, or about $57m of the company's $67m in annual revenues for the year, came from Google.
Firefox assigns the Google search site as the default for the browser's search bar; users can, however, change that to a rival search site if they wish. The browser also defaults to a Google URL for its home page.
Mozilla and Google last inked a two-year deal in 2006 that was to expire in November.
Last year, Baker said that she would not hesitate to walk away from the lucrative partnership if that was what was necessary to remain independent. "We've spent a lot of time and energy making sure that Google understands that it cannot turn us into an arm of Google," Baker said in an interview with Computerworld in October 2007. "If the protection of [our independence] would come into conflict with Google, or any of our search partners, we would opt for the community who built Firefox and love Firefox."
In the two years since Mozilla last signed with Google, the open-source developer's browser has increased its market share from 11.8 per cent to 19.2 per cent, according to Web metrics vendor Net Applications.