Google Inc. (GOOG) is making everyone who snubbed its unconventional initial public offering of stock regret their decision.

In the latest rebuke to its skeptics, Google wowed Wall Street with its first quarterly earnings report as a public company, propelled by a continued surge in online advertising distributed by its Internet-leading search engine.

The company said Thursday that it earned $52 million, or 19 cents per share, during the three months ended in September. That compared to $20.4 million, or 8 cents per share, at the same time last year.

The quarter offered Google the first chance to demonstrate how the company held up during a much-scrutinized IPO that has turned hundreds of its employees into millionaires. Investors were impressed with what they saw: shares of Google surged 12 percent, or $17.77, to $167.15 on the Nasdaq Stock Market (search). Google released its results after the stock market closed Thursday.

"This has probably become the ultimate momentum stock," said Janco Partners analyst Martin Pyykkonen, who believes Google's shares have become too expensive. "Still, you have to give them a high five. It was a very strong quarter."

The enthusiastic reaction reflects Google's robust revenue and earnings growth during the third quarter.

Google said it would have earned 70 cents per share, if not for charges related to stock-based employee compensation and a previously announced patent settlement with rival Yahoo Inc. (YHOO).

That was well above the mean estimate of 56 cents per share among analysts polled by Thomson First Call. Analyst forecasts had varied widely because Google hadn't provided any previous financial outlook and management has vowed to continue that policy.

Google's revenue for the third quarter totaled $805.9 million, up from $393.3 million last year. Google generated most of the revenue — $411.7 million — through ads displayed on company-owned sites. That's an important factor because Google doesn't have to share the money with other advertising partners.

Subtracting the commissions Google paid to deliver ads to other Web sites, the company's third-quarter revenue would have been $503 million, topping the mean analyst estimate of $456 million, according to First Call.

"Our business is working very well," Google CEO Eric Schmidt said Thursday in an interview. "There had been a lot of concern that we would go public and our employees would become distracted. But we did the IPO and then came right back to work."

Caris & Co. analyst David Garrity was pleased with Google's performance. "Companies are supposed to blow the numbers away the first quarter after an IPO and they did that, so hats off to them," he said.

Based on the latest price, Google's market value stands at $44 billion just six years after the company's inception. Co-founders Larry Page (search) and Sergey Brin (search), who began developing Google's search engine in a Stanford University dorm room, are now worth roughly $6 billion apiece.

Wall Street's lofty assessment of Google stems from the company's ability to turn its immensely popular search engine into a moneymaking machine that churns out text-based ad links related to the content displayed on a Web page.

Google lost some of its luster during an auction-style IPO marred by a series of hitches raised questions about management. Prospective investors also rebelled against the company's attempt to fetch a price as high as $135 per share.

Prodded by the backlash, Google lowered the IPO price to $85 per share. Since it started trading, the stock has climbed to heights that has surprised even the most bullish analysts amid a renewed buzz about one of the best-known names on the Internet.

The rapid run-up in Google's stock increased the pressure to deliver a strong quarter, particularly after online rival Yahoo Inc. announced a big earnings gain earlier this month.

Google's latest quarter shows the company is growing far faster than Sunnyvale-based Yahoo, said American Technology Research analyst Mark Mahaney. While Google's revenue doubled from last year, Yahoo's climbed 33 percent, excluding gains from an acquisition, Mahaney said. "The fundamentals look very impressive for Google."

Although excited about the company's achievements so far, Schmidt is trying to keep Google's nearly 2,700 employees on an even keel.

"We have really tried to ignore the stock price," Schmidt said. "I have tried to delete it from our focus."