SINA Corporation, operator of China's most used social networking site, posted US$13.2 million in first-quarter losses, a drop of US$5 million from a year earlier.
The losses were attributed to higher costs of labor and professional services, the company said in a stock exchange filing today.
"We'll focus on developing mobile applications, launch new products and add new sales channels to speed up monetization progress," Sina chairman and chief executive officer Charles Chao said today.
Sina Weibo had an average of 49.8 million daily active users as of March.
First quarter revenue grew 19 percent annually to US$126 million with advertising contributing US$93.4 million.
Weibo contributed US$18.8 million of advertising income, lower than US$21.3 million in the last quarter of 2012, due to the low season of January-March.
Last month, Sina announced strategic partnership with China's largest e-commerce company Alibaba Group and sold 18 percent of its Weibo shares for US$586 million.
Sina and Alibaba will work on new marketing models and create exclusive advertising channels for Alibaba's online retailers. Chao said this will not affect existing advertisers.
Operating expenses for the first three months totaled US$69.8 million, compared with US$64.1 million for the same period last year.
Sina is speeding up monetization of Weibo in the face of strong competition from other Internet giants like Tencent.