Fewer than 60 percent of European web users run Microsoft's Internet Explorer, according to a French-based metrics company, while more than 31 percent have switched to Mozilla's Firefox.
Microsoft's browser dipped under 60 percent for the first time in August, rallied slightly in September, but then dipped below that bar again during October and November, said XiTi Monitor, a web measurement site operated by Applied Technologies Internet of Merignac, France.
For November, IE's share of Europe's browser market was 59.5 percent, down a percentage point since June and off five points since April.
Firefox's share, meanwhile, has slipped nearly two percentage points since August, when it accounted for 33 percent of the European market. After falling to 31.2 percent the following month, Firefox ended November with a 31.1 percent share, the lowest number since May 2008.
Another Internet metrics firm, US-based Net Applications, had also noted a drop in Firefox's share during September, and attributed the decline to desertions to Chrome, the browser that Google introduced that month. Net Applications' numbers for Firefox, however, decreased much less dramatically, down just 0.2 percent from the month before.
But while Net Applications' data showed that Firefox quickly regained losses it had suffered to Chrome, and then added more users, XiTi's measurements indicate that Firefox's growth has essentially stalled.
Net Applications has also tracked the slow, steady decline of IE. Last month, said Net Applications, which monitors visitors to more than 40,000 sites, the majority of them US URLs, Microsoft's browser fell under a 70 percent share for the first time since the California company began monitoring browser market share.
According to XiTi, both Chrome and Opera Software's flagship Opera browser control larger shares in Europe than they do in the US. Chrome, for instance, ended November with a 1.1 percent share - Net Applications pegged it at 0.8 percent - while Opera owned a 5.1 percent share, more than seven times higher than the 0.7 percent measured by Net Applications.