Chinese micro-blogging service Weibo has filed to raise $500M in an IPO in the U.S.
The company had 129M users at the end of last year vs Twitter's 241M, while 2013 revenue almost tripled to $188M. However, the firm made losses of $38M and warned of uncertainty due to Chinese regulation (read censorship).
Weibo's filing comes ahead of an expected IPO submission from Internet giant Alibaba, which owns a 19% stake in Weibo. Sina (SINA) owns 78%.