Baidu's profits more than doubled in the second quarter of this year because of an increase in customers after rival Google lost market share.

Net income surged 118 percent to US$123.5 million, or 35 US cents per share, the company said yesterday.

Total revenue in the three months jumped 74 percent from a year ago to US$283.3 million.

The number of active online advertising customers rose 25 percent year on year to 254,000. It added 33,000 clients in the second quarter after a nationwide marketing program.

"We will continue to focus on user experience to ensure Baidu remains at the center of China's Internet ecosystem," Robin Li, its chief executive officer, said.

"Both big cities and second or third tier cities saw strong increase in customers, which is attributable to the increase of sales force," Shen Haoyu, senior vice president, said.

Baidu said it was in the process of developing search products for wireless Internet to adapt to new user behavior as more and more users access the web through handsets.

Li said he is "optimistic about the mobile Internet and there are R&D projects going on internally."

Baidu hopes to generate total revenue of US$324.4 million to US$333.3 million in the third quarter, or a 72 to 77 percent jump year on year.

Google recorded a 27.3 percent market share in the second quarter, down from the 29.5 percent in the previous quarter, according to a report by iResearch earlier this week.

Baidu accounted for 70.8 percent, the first time it had exceeded 70 percent. In the fourth quarter of 2009, Google's market share was 32.8 percent versus Baidu's 64.8 percent.

Google started to redirect users to its uncensored Hong Kong search site in late March but kept music, online maps and other services on China's mainland. Although it renewed its content provider license earlier this month, some advertising agencies had shifted to other search engines.