Microsoft's browser dipped under 60% 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%, 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% of the European market. After falling to 31.2% the following month, Firefox ended November with a 31.1% share, the lowest number since May 2008.

Another Internet metrics firm, U.S.-based , had during September, and attributed the decline to desertions to Chrome, the browser that Google Inc. introduced that month. Net Applications' numbers for Firefox, however, decreased much less dramatically, down just 0.2% 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.