Facebook CEO Mark Zuckerberg speaks during a news conference at Facebook headquarters in Palo Alto, California May 26, 2010. REUTERS/Robert Galbraith

By Supantha Mukherjee

(Reuters) - Shares of Facebook Inc (FB.O) hit a record high on Thursday after a surge in mobile advertising revenue helped the world's No. 1 social network trounce analysts' expectations for quarterly profit and revenue.

The company's shares, which touched a high of $76.74, were up 7 percent at $76.31 by midday on the Nasdaq.

At that price, Facebook's market value is just short of $200 billion, putting the company in position to overtake IBM Corp (IBM.N) as the fourth-largest U.S.-listed tech company.

The top three are Apple Inc (AAPL.O), Google Inc (GOOGL.O) and Microsoft Corp (MSFT.O).

At least 28 brokerages raised their price targets on the stock, by as much as $15 to a high of $100.

At $100, Facebook would be valued at more than $250 billion.

Facebook reported on Wednesday that its mobile advertising revenue grew 151 percent in the second quarter, accounting for about 62 percent overall ad revenue.

"Facebook has, so far, effectively addressed one of the most significant overhangs from its IPO days - the lack of mobile monetization," RBC Capital Markets analysts said in a note.

Facebook's initial public offering in May 2012 was widely considered to be a flop. The stock, priced at $38, fell for months after the debut as investors worried about the company's ability to make money from mobile advertising.

With people increasingly accessing the Internet from smartphones and tablets, companies such as Facebook, Google Inc (GOOG.O) and Twitter Inc (TWTR.N) have been looking for ways to generate more revenue from the smaller screens.

"We estimate that FB accounts for $1 of every $5 ad dollars spent on mobile devices," Needham and Co analysts wrote in a client note.

Facebook now represents about 20 percent of total time spent on mobile devices, according to research firm comScore data.

"We think 2Q represents further validation that Facebook can continue to drive mobile ad revenue growth through better ad targeting, relevancy and quality, and through continued growth in advertiser demand in its ad auction," JP Morgan analysts wrote in research report.

JP Morgan, which kept its "overweight" rating on the stock, raised its price target to $90 from $80.

Of the 43 analysts covering the stock, 37 have a "buy" or a higher rating on the stock and six a "hold". There are no "sell" ratings, according to StarMine data.

Facebook's quarterly revenue of $2.91 billion beat the average analyst estimate of $2.81 billion, according to Thomson Reuters I/B/E/S.

"It was a very impressive quarter on top of what we believe were very high Street expectations," Barclays Equity Research analyst Paul Vogel wrote in a note.

While the average price per ad rose 123 percent year-over-year, total ad impressions fell 25 percent.

"The sharp rise in pricing was the result of an increase in proportion of newsfeed ads, which generally command higher pricing relative to other formats, and the decline in impressions was due to an increase in mobile usage," Macquarie Research analysts wrote.

Facebook, whose newsfeed ads inject paid marketing messages straight into a user's stream of news and content, said it now had 1.32 billion monthly users, of which about 63 percent access the service every day.

Up to Wednesday's close, Facebook's stock had more than quadrupled since touching a low of $17.55 in September 2012.

Facebook shares hit their previous record high of $72.59 on March 11.





(Reporting by Supantha Mukherjee in Bangalore; Editing by Ted Kerr)