Google (GOOG) this afternoon reported Q4 revenue and profit below analysts’ estimates.

Revenue in the three months ended in December rose 25% to $8.13 billion, yielding EPS of $9.50.

Analysts had been $8.43 billion and $10.51 per share in profit.

The company’s owned and operated Web sites saw revenue rise 29%, to $7.29 billion, while affiliate sites’ advertising revenue was up 15% in the quarter, at $2.88 billion.

Google’s paid click volume rose 34%, year over year, and rose 17% from the prior quarter, it said. The average Google was paid for each click, so-called cost-per-click, dropped 8%, while the company’s “traffic acquisition cost” rose by  18%, year over year, to $2.45 billion.

The company ended the quarter with $44.6 billion in cash and equivalents. With roughly 325 million shares outstanding, that equates to about $137 per share in cash.

Google shares are down $54.53, almost 9%, at $585.04.

Google’s conference call with analysts gets under way now, at 4:30 pm, Eastern time, and you can catch the webcast of it here.

Update: In a brief note just out, Citigroup’s Mark Mahaney writes that the company’s interest and other income line item was a negative $18 million, whereas he had expected a positive $260 million; and the effective tax rate of 22% was higher than the 19% he had been expecting. Mahaney also notes that international revenue was up just 6%, on a gross basis, which was well short of the 9% he was estimating. Excluding hedges and foreign exchange impact, international revenue was up 28%, lower than the 31% growth in the prior quarter. Mahaney takes that as a “neutral-ish” trend.

And Susquehanna Investment Group’s Herman Leung, who has a “Positive” rating on Google shares, writes that the miss was largely a factor of revenue coming up short, as “margins held stable,” in his view. He notes the 8% drop in cost-per-lick was in contrast to his expectation for a 6.1% decline, and what was Street consensus for a 3.2% decline.