Google revenues worse than expected
Google reported a 27% increase in revenues for the last three months of 2011, but even that was not good enough to meet Wall Street estimates, sending the shares tumbling.
Google shares fell 10% in after-hours trading to $575.
It reported 3-month revenues of $10.6bn (£6.8bn). Its net profit rose 6.4% to $2.7bn.
"Google had a really strong quarter ending a great year," said chief executive Larry Page.
"I am super excited about the growth of Android, Gmail, and Google+, which now has 90 million users globally - well over double what I announced just three months ago."
It came as fellow technology firms Microsoft and Intel also posted results for the same period.
Microsoft posted flat earnings of $6.62bn in the same quarter, seeing strong business demand for software and services.
Intel, the world's largest chipmaker, posted a better-than-expected 6% rise in earnings to $3.36bn, even though floods in Thailand knocked out factories that produce hard drives and components.
'Pressure' outside US
Speaking to BBC Radio 5 live, Graham Palmer, head of Intel, said: "We're seeing strong growth in the merging PC markets.
"China now has 20% consumption of the personal PC market - there are about one million PCs 'consumed' every day globally and there is still lots of growth, especially the emerging markets of Brazil, Russia, India and China."
But analysts were less impressed with Google's figures.
"Expectations were very high and they have missed that," said Trip Chowdhry, from Global Equities Research.
"Unlike Microsoft and Intel, estimates for Google have been rising for a few months."
The number of clicks on Google's search adverts rose significantly in the fourth quarter, but the amount that Google was able to charge advertisers for each click fell 8%.
"Expectations had got ahead of themselves for Google, largely because investors don't have a good feel for what happens outside the US," said Jordan Rohan from Stifel Nicolaus.
"North America has remained strong, but there are parts of the world where there's a lot of economic pressure. I would have to assume Europe, particularly Germany and some others, undergoing austerity measures. The underlying demand in those countries is weak."
For the full year, Google reported a 29% rise in revenue to $37.9bn, with net profit up 14% to $9.7bn.