Most Western internet executives frown at the notion that Chinese internet companies are innovators. But what Sina, the country’s largest news portal, is doing with its microblog may change their minds.

Sina’s microblog, or Weibo, started in 2009 as little more than a Twitter clone – with Chinese characteristics in that it self-censors content, a necessary condition for any internet company that wishes to remain online in China.

But, as I report on ft.com, the service has now moved far beyond that. Over the past few weeks, the service has added a location-based service resembling Foursquare and an instant messaging tool. That comes in addition to social networking functions such as discussion groups and virtual meeting and market places – a mixture that makes Sina Weibo a more complete and varied social media platform than either Twitter or Facebook.