The latest US search engine rankings from comScore show that only Google and Microsoft grew their market share while Yahoo!, Ask and AOL lost share.
Microsoft's Bing outpaced Google in October, adding 0.3 percentage points to 11.5% market share.
Google increased its lead by 0.2 percentage points to 66.3%.
Second placed Yahoo! slipped by 0.2% percentage points to 16.5%.
Ask was in 4th place with 3.6% share, losing 0.1 percentage points.
AOL was in fifth place losing 0.2 percentage points to 2.1%.
Microsoft increased its number of searches in October by 7% compared with a 4% increase by Google.
More details are here.
Ask recently pulled out of the search market; it will be interesting to see which company will pick up its 3.6% market share. Are Ask users deliberately not using Google? That would mean a big boost to Microsoft in the November numbers.
The introduction of Google Instant has forced comScore to change the way it analyzes its results. This is explained here: comScore September 2010 Search Reporting Enhancements (comScore Voices)