Chinese online and wireless value-added service media company Sina Corporation announced its unaudited financial results for the quarter ended September 30, 2010, and said net revenues grew 12% year over year to USD108.2 million but the company expects lower results in the following quarter.

Advertising revenues grew 27% year over year to USD81.0 million, and non-advertising revenues decreased 16% year over year to USD27.3 million. Net income attributable to Sina increased 87% year over year to USD31.3 million, or USD0.48 diluted net income per share attributable to Sina.

“For the third quarter of 2010, Sina’s online advertising business, which excludes the adjusted results of Sina real estate advertising, grew 50% year over year to reach a historical high. The strength of Sina’s online advertising business has accelerated our bottom line growth.” said Charles Chao, CEO of Sina. “On the operation side, we believe the continued momentum around our mini-blog Sina Weibo and the formation of strategic partnerships with MSN and NBA will further enhance our leadership position in China’s online media space.”

However, Sina estimates that its non-GAAP net revenues for the fourth quarter of 2010 will be between USD103 million and USD106 million, with non-GAAP advertising revenues to be between USD81 million and USD83 million and non-GAAP non-advertising revenues to be between USD22 million and USD23 million.

Gross margin for the third quarter of 2010 was 60%, up from 59% for the same period last year. Advertising gross margin for the third quarter of 2010 was 63%, up from 61% for the same period last year. Non-GAAP advertising gross margin for the third quarter of 2010 was 63%, compared to 59% for the same period last year. The increase in non-GAAP advertising gross margin was mostly due to revenues growing faster than advertising cost of revenues. MVAS gross margin for the third quarter of 2010 was 38%, compared to 54% for the same period last year. The decline in MVAS gross margin was primarily due to product mix and increased revenue share with MVAS partners.

Operating expenses for the third quarter of 2010 totaled USD36.0 million, compared to USD38.3 million for the same period last year.

As of September 30, 2010, Sina’s cash, cash equivalents and short-term investments totaled USD857.0 million, compared to USD821.5 million as of December 31, 2009. Cash flow from operating activities was USD51.3 million for the third quarter of 2010, compared to USD29.1 million for the same period last year.