Chinese Internet portal Sina.com (Sina) said its unaudited financial results for the quarter ended March 31, 2008 show net revenues increased 39% year over year to US$71.3 million.

In particular, Sina.com's advertising revenues increased 51% year over year to US$47.8 million and non-advertising revenues increased 20% year over year to US$23.5 million.

"We had an excellent first quarter to start the year 2008," said Charles Chao, CEO of Sina. "The growth of our advertising revenues has been accelerating and our mobile business has continued its rebound. Our outstanding performance in the advertising business is a strong indication that Sina's position as the leading online media and branded advertising platform in China has been further enhanced. We are equally pleased with our continued success in building our Web 2.0 product lines with the launch of Sina Space and Sina TV."

Gross margin for the first quarter of 2008 was 59%, flat over the same period last year and down from 62% last quarter. Advertising gross margin for the first quarter of 2008 was 60%, compared to 58% in the same period last year and 64% in the previous quarter. Excluding stock-based compensation, non-GAAP advertising gross margin for the first quarter of 2008 was 62%, compared to 59% in the same period last year and 65% in the previous quarter. The year over year increase in advertising gross margin was mainly due to advertising revenue growing faster than advertising cost of sales. On a sequential basis, advertising gross margin declined due to lower advertising revenues while bandwidth and content costs increased.

Mobile value-added services gross margin for the first quarter of 2008 was 56%, compared to 60% in the same period last year and flat over last quarter. The year over year decrease in MVAS gross margin was mainly related to increased content and channel costs.

Operating expenses for the first quarter of 2008 totaled US$28.7 million, an increase of 25% from the same period last year and an increase of 1% from last quarter. Net income for the first quarter of 2008 was US$16.1 million, or US$0.27 diluted net income per share, compared to US$8.6 million, or US$0.15 diluted net income per share, for the same period last year.

As of March 31, 2008, Sina's cash, cash equivalents and short-term investments totaled US$511.6 million, compared to US$382.7 million and US$478.0 million as of March 31, 2007 and December 31, 2007, respectively.