SHANGHAI, Aug. 7 -- CHINESE portal Sina.com posted a 39 percent increase in second quarter earnings over the same period last year on strong advertising sales, the company said today.

Net income was US$16.1 million, or 27 US cents per share. Sales grew 11 percent year on year to US$59.8 million, within the upper range of the company's guidance. Ads sales jumped 40 percent from a year ago, beating the Beijing-based Website's expectation of up to US$41 million.

Charles Chao, chief executive officer of Sina, noted the results ``demonstrate our strength in our core online advertising business,'' which has kept growing by 40 percent or more year-on-year for the fifth consecutive quarter.

Sina, China's largest portal, has forged a strategic partnership with Google in June on Web search, news and advertising as its own search engine, iask.com, was losing share to China's search market leader Baidu.com. Google still trails far behind.

Sina estimated that total revenues for the third quarter will range from US$63 million to US$65 million, with ads sales between US$45 million and US$46 million.