The search giant saw its market share drop to 88% in December 2012.
According to Experian, 2.7 billion visits were made to UK search engines in December 2012. This represents a 17% increase year-on-year for UK search.
Google market share dropped below 90% for the second month in a row while search rivals like Bing, and Yahoo increased their overall market share.
"Clearly, Google still maintains a huge competitive edge over the other search engines in the UK market," said James Murray, Digital Insight Manager at Experian Marketing Services. "There are seven times more searches conducted on Google Sites than on all the other search engines combined. However, this is encouraging news for Microsoft as bing once again starts to gain some momentum and traction in the UK search market."
Microsoft sites led by Bing increased their search market share by 0.19% for a total share of 4.99%. Yahoo sites also increased their market share by 0.08% bring its total market share to 3.58%.
"Bing's availability across multiple Microsoft devices and becoming the default search engine on sites such as Facebook has also contributed to an increase in market share as the way in which consumers use search engines continues to diversify," added Murray.
Overall, December 2012 saw an increase in searches largely attributed to the Christmas sales period. UK retail sites received around 2.8bn visits during the season, setting an online retail record.