Sina Corp, the owner of China's third-most-visited website, said it may seek other search engine providers to replace Google Inc after the US company moved its Chinese site offshore.

"If they cannot continue to provide high-quality service then we have to consider our alternatives," Sina Chief Executive Officer Charles Chao said in a conference call today. Sina is assuming it won't generate revenue from its partnership with Google, Chao said.

Sina may follow billionaire Li Ka-shing's Tom Online Inc in dropping Google as a partner in the world's biggest Internet market by users.

Marsha Wang, a Beijing-based spokeswoman at Google, declined to comment.

California-based Google accounted for 30.9 percent of percent of China's online search market in the first quarter, dropping from 35.6 percent three months earlier, according to data from Analysys International. Baidu's market share rose to 64 percent from 58.4 percent, according to the Beijing-based researcher.

Profit rises

Tom Online, a unit of Li's Hutchison Whampoa Ltd, in March selected Baidu Inc to replace Google as its partner for Web searches in China. Motorola Inc said that month it stopped including Google's search engine on a mobile-phone offered in the Chinese market.

Sina yesterday said first-quarter profit more than doubled to $24.4 million from $9.75 million a year earlier. That compares with the $15.6 million average of 10 analysts' estimates compiled by Bloomberg.

Internet advertising sales rose 26 percent to $54.3 million, Sina said. The growth in the online ad market in China is continuing in the second quarter, Chao said today.

Second-quarter sales may rise to between $90 million and $93 million, Sina forecast. This compares with the $94.2 million average of analysts' estimates compiled by Bloomberg.

Sina shares rose $4.15, or 12 percent, to $39 at 9:45 am New York time in Nasdaq Stock Market trading, the most since June 1. They have dropped 14 percent this year.