Updated from Oct. 18

Google ( GOOG) is back.

After a rare earnings miss in its second quarter, the company on Thursday delivered third-quarter results that trumped Wall Street's aggressive top- and bottom-line estimates.

But true to form, the company was vague about its plans to enter the mobile, display, and video ad markets that investors expect it to storm next. Management did talk about the potential that each market holds, however.

Shares of the search giant rose $12.13 early Friday to $651.75. Even the modest 1.9% gain is impressive considering the stock has rallied almost 30% since August lows, hitting an all-time high Thursday above $641, and investors were widely expecting a promising quarter.

The strong performance should once again rectify the confidence of some investors who were jolted by last quarter's miss. And Google's showing should also mean that investors give the company's management the benefit of the doubt as it hopes to storm new arenas.

But for now, Google's core search business remains the star of the show. Continued gains in market share combined with an ability to make money off searches helped Google deliver its strong quarter, CEO Erich Schmidt said in a conference call for investors.

But with Google's search juggernaut on track, analysts turned their focus to Google's plans to push into new markets. And there, the company seemed to keep its options open while remaining bullish on its prospects of moving beyond search.

Asked about the company's proposed bid for ad technology company DoubleClick, which would make Google a player in the online display-ad market, Schmidt said only that he was optimistic, and that "it would be premature to suggest anything more about timing."

The company also said it was upbeat on the progress of video ads it had introduced on its YouTube video-sharing service earlier in the quarter. But it declined to say when the ads may start helping the bottom line, and Google co-founder and President of Technology Sergey Brin noted that Google would continue to experiment with new formats.

The company also pointed to the importance of the mobile market for its future strategy. "Mobile search is growing rapidly for us but is still a small percentage overall, which is a big frustration for us," Schmidt said. But management was vague in outlining more specific plans.

Google also said headcount grew by a hefty 2,130 over the quarter. The company now employs nearly 16,000 people.

However, if the company continues to deliver such strong numbers, it will be hard for investors to find fault.

For the quarter, the company earned $3.91 a share on a pro forma basis, excluding certain costs -- beating Wall Street's $3.78-a-share estimate. Net revenue, excluding the fees Google pays search-ad partners, was $3.01 billion, breezing past the $2.94 billion Thomson Financial target.

Though Google faced high expectations, investors were heartened with the company's performance over the quarter.

"Most people expected a very strong quarter on the top and bottom line, and Google delivered," said Darren Chervitz, the director of research at Jacob Asset Management, which owns Google shares. "It looks like another impressive quarter for what has become a near machine in terms of achieving earnings."

Chervitz said he was particularly impressed by the company's ability to keep expenses in check this quarter. "They admitted they over-hired last quarter, and it seems like they have done a much better job of handling growth this quarter."

On a reported basis, Google made $1.07 billion, or $3.38 a share, for the quarter ended Sept. 30, up from the year-ago $733 million, or $2.36 a share. Gross revenue rose 57% from a year ago to $4.23 billion.

Paid clicks were up 45% over the third quarter of 2006 and up about 5% sequentially.

International revenue was $2.03 billion, accounting for 48% of gross revenue for the quarter. That compares to 44% for the same period a year ago and 48% for the second quarter.

Operating expenses were $1.25 billion, or 30% of gross revenue, compared to $1.21 billion, or 31% of revenue, in the second quarter. The company also said it spent $553 million in capital expenditures over the quarter, with the bulk of spending going to IT infrastructure like data centers and networking equipment.

"We are very pleased with the impressive growth we experienced across our business," said CEO Eric Schmidt. "Our core search advertising business experienced continued momentum driven by growth in monetization and traffic, and we are creating a wider and deeper ads system through our focus on innovation, bringing more ad formats to our advertisers."

Google's strong numbers follow on the heels of solid reports at rival Yahoo! ( YHOO) and online auctioneer eBay ( EBAY). The stock failed to lift off in early postclose action, though, reflecting the strong run Google has made lately. Heading into Thursday's report, Google shares were up more than 29% since the market bottomed on Aug. 16.

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