China will launch some eight Beidou navigation satellites by 2012, said?Ran Chengqi, a leading navigation satellite expert,?in Shanghai on Wednesday.

China has sent eight Beidou satellites into orbit, as the latest was launched in April this year, said Ran, director of China Satellite Navigation System management office.

He made the remarks at the second China satellite navigation academic annual meeting.

Beidou satellite navigation system will finish comprehensive tests as of October 2011 and have the capacity to provide "preliminary" services for most parts of China, Ran said.

By 2020, about 35 satellites will form Beidou's global satellite navigation system, Ran added.

Ran forecast China's satellite navigation sector would see about 400 billion yuan (US$61.84 billion ) in annual output value by 2020.

China started building its own satellite navigation system in 2000 to end its dependence upon the US GPS system when it sent two orbiters into space as a double-satellite experimental positioning system.

Beidou, or dipper, as the system is named, is designed to provide navigation, time and short message services in the Asia and Pacific region before 2012 and will be capable of providing global navigation services by 2020.

According to experts, the performance of the Beidou system in global competition in the next?10 years will largely rely on three aspects: user feedback, the overall construction of China's basic industries and support from government policies.