Google continues to hold its own atop the search market despite being targeted by Microsoft and its well received Bing search engine in recent months.
Nielsen reported that Google's engine answered some 6.7 billion search queries in the US last month, accounting for 67.3% of all online searches. The company's share in November was 65.4%.
Google's share has increased by more than 6% since July, when held 61% of the market in July, according to Nielsen.
Nielsen said that Yahoo had the second highest market share in December - 14.4%. The Yahoo share is down by just under 1% from November, Nielsen said.
Microsoft's Bing also showed a slight slip in December. Neilsen listed Bing's November share at 10.7% compared to December's 9.9%.
Bing, unveiled last June, made strong gains in the search market - in the US and globally - early on. But Bing's momentum started to stumble a bit in September when it saw its first slip in market share.
Microsoft and Yahoo in July announced plans to join forces in a search and online advertising deal to better take on Google.