Mozilla and Google have agreed to continue their search agreement for another three years, amounting to a payout of almost $1 billion, according to a report from the web site AllThingsD.

Google bested Microsoft and Yahoo, which were also jostling to link up with Firefox as competition remains intense in the search, and by extension, the browser market. In particular, Microsoft has tried mightily to push its Bing search engine ahead in the market.

The funding comes as a major boost for Mozilla. The open-source browser’s revenue last year totaled $123 million, 84 percent of which came from Google, according to AllThingsD.

Microsoft’s Internet Explorer retains the dominant share in the browser market, ahead of Google Chrome and Firefox, with 40.63 percent market share in November, up from 40.18 percent in October, according to a report from StatCounter Global Stats.

But Google Chrome is making gains, posting 25.96 percent of global browser usage in November, up from 25 percent in October, and from 13.35 percent in November 2010.

In contrast, Firefox’s market share has slipped. It accounted for 25.23 percent in November, down from 26.39 percent in October, and from 31.17 percent in November of 2010.