Even Internet giants don’t always get it right: Google accidentally releases earnings prematurely, sending shares plummeting.

A pending press release with Google Q3 financials was released hours prematurely overnight, showing net profit down to $2.18 billion compared to $2.73bn in same time 2011.

The announcement cock-up forced share trading to cease for some 45 minutes, yesterday, and fell over 8% in total.

The disappointing profit result for the quarter ending September 30 was due to rising costs and the newly Googled Motorola, which recorded a $527 million operating loss in Q3.

A ‘Pending Larry Quote’ referring to Google’s CEO was also contained in the premature PR which stated:

“At just 14 years old, we cleared our first $US14 billion revenue quarter. I am also really excited about the progress we’re making creating a beautifully simple, intuitive Google experience across all devices.”

Page later apologised for the “scramble” blaming the disaster on the company’s financial printer, R.R. Donnelley, who “filed our draft 8K earnings statement without authorization.”

Operating income also slipped to $2.74 bn, or 19% of revenues, compared to of $3.06 bn, in Q3 2011.

Google’s earnings per share also fell to $6.53, compared to $8.33 in Q3 last year.

Revenue rose 45%, however, to $14.10bn, with Ads ($11.53 bn, +19%) and Sites revenue ($7.7 bn +15%) all rising, although International Revenues (outside the US) slipped 1% to 53% of Google’s total revenues, compared to 54% in Q2.

However despite the profit slump, Page insisted: “we had a strong quarter”.

(The ‘pending Larry Quote’ was still contained in the final PR sent out hours later).

Google shares fell over 8% to $695 but rose 1% to over $700 in afterhours trading on the Nasdaq after Page quelled analysts fears at the earnings call, held after the announcement.

The change from PC searches to mobile wont affect Google’s future performance, Page insisted during an earnings call with investors:

“Monetization on mobile queries is a significant fraction of desktop. We’re living the best of both worlds. We’re able to move existing ads over to mobile and able to really innovate using Android and our strength of having ads on other platforms.”

Google is “uniquely positioned to get through that transition and profit” from the move to mobile Internet, he insisted, citing Google’s Android OS, the most popular mobile platform, globally.

The profit slump appears to be the result of rising costs at Google including data center operational expenses, content acquisition and manufacturing costs, which trebled to $ 3.78bn or 27% of revenues, in the third quarter compared to $1.17 bn, or 12% a year earlier.

The big change during the quarter was taking phone maker Motorola fully under its wing, which reported revenue $2.58 bn, or 18% of consolidated revenues, although cited $182m amortization of Moto-related assets.

But analysts weren’t fazed by the profit dip, saying the less than stellar results “just a hiccup in Google’s climb” and is “on the growth side of the wave,” Independent tech analyst Jeff Kagan told AFP.

The Internet king has 53,546 full-time employees (36,118 Google + 17,428 Motorola staffers) at the end of its third quarter a  just 50 less than Q2 head count.