* Advertising revenue up 36 percent
* Monthly active users top 1 billion, of which 604 million were mobile
* Zuckerberg not pleased with gaming revenue
* Shares up nearly 13 percent
SAN FRANCISCO, Oct 23 (Reuters) - Facebook Inc grew mobile advertising revenue several times in the third quarter, a faster-than-expected pace that helped drive shares in the world's No. 1 social network nearly 13 percent higher.
Facebook said on Tuesday that it now gets 14 percent of its advertising revenue from mobile ads, helping to reassure investors that the social network is beginning to figure out how to earn money off smartphone and tablet users.
Mobile ad revenues totalled roughly $150 million, up from an estimated $40 million to $50 million in the second quarter and almost nothing in the first.
``This certainly dispels the most bearish view, that Facebook couldn't monetize people on phones or tablets,'' said Colin Sebastian, an analyst with Robert Baird & Co.
``In about a six-month period they've actually started to generate decent revenues form their mobile applications,'' Sebastian added, though he said Facebook still needs to show that its mobile ads can command the same rates as its traditional ads and that they can deliver results for marketers.
Mobile advertising has been among the key investor concerns hanging over Facebook, helping slash more than $40 billion off its market value since its May IPO. As its users increasingly access the social network with their smartphones, Facebook has struggled to transition its business to mobile devices.
The mobile ads helped reignite Facebook's overall advertising business during the third quarter, following several consecutive quarters of slowing revenue growth that raised questions about Facebook's long-term prospects.
Advertising revenue increased 36 percent to $1.09 billion, up from 28 percent growth in the second quarter. B ut revenue from its payments and other businesses increased just 13 percent to $176 million.
Mark Zuckerberg, the 28-year-old chief executive who created Facebook in his Harvard dorm room, said mobile was the ``most misunderstood aspect'' of the company and took issue with the ``myth'' that Facebook could not earn money on mobile.
``Over the long run we're going to see more monetization per time spent on mobile than on desktop,'' Zuckerberg said on a conference call with analysts on Tuesday.
The company's shares leapt nearly 13 percent to $21.97 in after-hours trading on Tuesday.
Facebook said it had crossed the 1 billion threshold for monthly active users by Sept. 30, of which 604 million were mobile users, a gain of 61 percent from a year earlier.
The shift to mobile has challenged many of the Web industry's top companies. Google Inc is the No.1 provider of smartphone software with its Android operating system. But the company missed Wall Street's revenue targets in the third quarter, with some analysts blaming the shortfall on its increasing reliance on lower-priced mobile ads.
Social game maker Zynga Inc, which announced layoffs of 5 percent of its staff on Tuesday, has suffered as it struggles to translate its hit games to mobile devices and as the use of its games on Facebook's service declines.
NOT PLEASED WITH GAMING
Zynga's woes were visible in Facebook's results, with Facebook's payments revenue from the maker of Farmville down 20 percent year on year.
Zuckerberg said he was not pleased with revenue from gaming, but said that beyond Zynga - which accounts for 7 percent of Facebook's total revenue - the situation was brighter.
``The interesting thing is that the rest of the games ecosystem has actually been growing. Our monthly payments revenue from the rest of the ecosystem increased 40 percent over the past year, since payments has been adopted,'' he said.
Zuckerberg also said Instagram, the photo-sharing app that Facebook acquired for roughly $750 million this year, now has 100 million users, up from 27 million when Facebook bought the company.
Facebook posted a net loss of $59 million or 2 cents a share in the three months ended Sept. 30 after booking a big provision for income taxes. Excluding share-based compensation and income tax adjustments, it earned 12 cents a share, a penny higher than the average analyst expectation.
Facebook Finance Chief David Ebersman said the company would continue to invest aggressively during the fourth quarter, though the company did not provide a specific financial outlook, in keeping with its previous practice.
Ebersman said that the total number of ads that Facebook delivered in the third quarter increased 27 percent year-on-year and that the average price per ad increased 7 percent.
Facebook's third-quarter mobile revenue marked a big jump from the second quarter, when Facebook said that it was generating more than $1 million a day from a new class of ads that appear in users' newsfeeds. Facebook said that roughly half of that revenue was from mobile ads, suggesting that mobile advertising revenue totaled $45 million in the second quarter.
Stifel Nicolaus analyst Jordan Rohan said that Facebook's mobile ad revenue was impressive, but said that Facebook needs to proceed carefully so as not to damage the user experience by overloading its service with too many ads.
And he said that Facebook's desktop PC advertising business appeared to have shrunk by about $40 million from the second quarter. Rohan said he would rather see the desktop ad business remain stable as the mobile ad business grows.
Facebook's third-quarter revenue of $1.26 billion was a hair above the average analyst expectation of $1.23 billion, according to Thomson Reuters I/B/E/S.