A man holds an iPhone as he visits Sina 's Weibo microblogging site in Shanghai May 29, 2012. [Photo/Agencies]

Sina Corp's Weibo will be valued at a lower-than-expected $3.46 billion when it goes public on the Nasdaq on Thursday. The Twitter-like microblogging service, owned by web portal Sina Corp, sold 16.8 million American Depositary Shares (ADSs) for $17 apiece, raising $285.6 million, an underwriter told Reuters.

The company had planned to sell 20 million ADSs at between $17 and $19 per share.

Weibo will add to the list of Chinese companies flocking to the US IPO market in their biggest numbers since 2010, drawn by soaring valuations for tech start-ups.

Chinese e-commerce giant Alibaba Group , which invested $586 million for an 18 percent stake in Weibo, is expected to file for a widely anticipated share sale as early as Monday, according to sources.

Alibaba rival JD .com filed for a $1.5 billion US listing in January.

Since its launch in 2009, Weibo has become the country's water cooler, a place where nearly 600 million Internet users opine on everything. Weibo had 143.8 million monthly active users in March.

The company's revenue almost tripled to $188.3 million in 2013 from a year earlier, while net loss narrowed to $38.1 million from $102.5 million.

Weibo's shares are expected to begin trading under the symbol "WB" on the Nasdaq on Thursday. Gold man Sachs (Asia) LLC and Credit Suisse were the lead underwriters to the offering.