Chinese Internet company Baidu Inc more than doubled its second-quarter profit, beating Wall Street expectations, as a surge in new advertising customers helped boost the company's revenue.

Baidu shares rose to $76.20 after hours after closing down 73 cents at $73.31.

Baidu continues to outperform across the board driven by a strong search advertising market in China, the launch of its Phoenix Nest (advertising) platform and share gains from Google Inc China, said Kaufman Brothers analyst Mayuresh Masurekar.

Baidu said its number of active online marketing customers totaled 254,000 in the second quarter, a 25.1 percent increase from the year-earlier period, and the company's largest gain since the fourth quarter of 2008.

Baidu said revenue in the three months ending June 30 totaled $282.3 million compared with $160.7 million a year ago. Analysts, on average, had expected revenue of $276.7 million, according to Thomson Reuters I/B/E/S.

The company's net income was $123.5 million, or 35 cents a share, compared with $56.1 million, or $1.61 a share a year ago, before Baidu implemented a 10-for-1 stock split. Analysts, on average, were expecting earnings per share of 31 cents.

Baidu said it expected revenue between $324.4 million and $333.3 million in the third quarter. Analysts are expecting revenue of $321.6 million.

Baidu owned 70.8 percent of China's search market in the second-quarter, a 3 percentage point increase over the last quarter, said iResearch.

No.2 player Google has faced difficulty in the world's largest Internet market since pulling out from the market earlier this year on censorship concerns and after a hacking incident. Google's market share fell to 27.3 percent in the second quarter from 29.5 percent in the previous quarter.

(Reporting by Alexei Oreskovic and Melanie Lee; editing by Bernard Orr)