Sina Weibo has sold fewer shares than expected in its US IPO which has been priced below expectations, a report said Thursday, ahead of its listing which takes place after selloffs on Wall Street. The Beijing-based firm, often described as China's version of Twitter, sold 16.8 million US depositary shares at $17, raising $285.6 million before the sale of any additional shares to underwriters, Dow Jones Newswires said, quoting two people familiar with the deal. Those figures are well below the 20 million shares and $340 million which it had been aiming for -- reflecting a cautious mood after the tech-weighted Nasdaq index tumbled for more than three weeks. The pricing is at the low end of the $17-$19 range at which the social networking company had been expected to offer its shares. In March, Weibo had estimated the value of its initial public offering at as much as $500 million. Sina Weibo -- launched in August 2009 to provide services akin to Twitter which is banned in China -- is a leading social media site in a country with the world's largest population of Internet users at 618 million. But it is facing questions about the size of its user base as well as rising competition from local rivals including Tencent's WeChat, an instant messaging platform that allows users to send text, photos, videos and voice messages over mobile devices. Weibo's ascent has also hit speed bumps due to a social media crackdown by Beijing, which tightly controls online activity. The ongoing troubles in the Nasdaq -- fuelled by concerns that some tech stocks such as Facebook and Netflix are overpriced -- has hit a number of recent IPOs. All five companies that went public in New York on Monday and Tuesday offloaded their shares for less than they had forecast. On Wednesday, an offering by Sabre Corp, a tech company specialising in travel booking, saw it sell 39.2 million shares at $16 a share, raising $627.2 million -- below expectations for a sale of 44.7 million shares for up to $20 that could have made almost $900 million.