The earnings report, released hours ahead of schedule due to an error on Thursday, revealed slowing sales in Google's core Internet advertising business.

The quarterly earnings missed expectations for the second time in a year but analysts said the decline was a short-term trade-off as mobile advertising revenue becomes a bigger part of its business.

Chief Executive Larry Page, speaking on an earnings call, said that Google's mobile business, which includes app sales and advertising, was now generating revenue at an annualized run rate of $8 billion, up from about $2.5 billion last year.

"This run-rate ... speaks to how GOOG has positioned itself to win regardless of platform," Nomura Equity Research's Brian Nowak wrote in a note, although he cut his price target on the stock to $840 from $900 because of the short-term outlook.

Google shares closed down 8 percent at $694.37 on Thursday. The stock was up 1 percent at $700 in premarket trading on Friday.

Piper Jaffray & Co, RBC Capital Markets, Raymond James, Robert W. Baird & Co, Susquehanna Financial Group, BMO Capital Markets and Evercore Partners also lowered their outlook on the Google stock by an average of $44.14.

Analysts at Barclays Capital, however, raised their price target by 4 percent to $780.

In a note titled "3Q Results Disappointing but Not Alarming," Barclays analyst Anthony DiClemente said Google's revenue missed on slowing click volume growth, but also blamed the negative impact of foreign exchange rates.

"We believe dislocation in shares creates a buying opportunity, and we like GOOG into 4Q, as we believe the company can benefit from ecommerce tailwinds and moderation in CPC (cost per click) declines on easier (comparables)."

For the fourth consecutive quarter, Google reported a decline in average CPC, a critical metric that measures the price advertisers pay the company.

Advertisers on Google's network pay a smaller fee for mobile display ads compared to a similar ad on PCs.

Net revenue growth at Google's main Internet business increased 17 percent year-over-year -- the first time growth in that business has fallen below 20 percent since 2009.

Google finance chief Patrick Pichette stressed on the conference call that the revenue growth rate would have been higher if the impact of currency rates had been backed out.

"We are incrementally more positive following the call given our belief that despite any near-term fluctuations from mobile monetization and FX, Google's franchise is intact and remains one of the most reliable growth stories on the Internet," Piper Jaffray's Gene Munster said.

MOTOROLA - DEAL GONE BAD?

Persistent losses at Google's recently acquired cellphone business, Motorola Mobility, were further exacerbated by a faster-than-anticipated fall in revenue for that unit.

RBC analyst Sean Kim said margins were likely impacted by Google's Nexus 7 tablet and higher-than-expected losses at Motorola Mobility Inc (MMI).

"Going forward, we continue to expect somewhat elevated level of losses at MMI and some margin degradation due to Nexus 7," Kim said.

Google launched Nexus 7, its first tablet, earlier this year to take on Amazon.com Inc's Kindle Fire and Apple Inc's iPad, but the low $199 price tag and related marketing costs weighed on margins.

"Marketing was higher primarily due to increased advertising for the Nexus 7 tablet," Raymond James' Aaron Kessler said.

(Reporting by Himank Sharma in Bangalore; Editing by Maju Samuel)

• A Permanent Economic Emergency