China has successfully launched its fourth satellite, forming part of its global navigation network called Beidou.

The satellite was placed in orbit atop a Long March 3 carrier rocket, according to Xinhua.

The system will join three satellites already in orbit, and eventually create a constellation of 35 satellites.

Beidou, a Chinese equivalent of the US global positioning system, will provide navigation, time and short-message services in the Asia and Pacific region by 2012. By 2020, the system will be able to offer global navigation services.