China has opened its domestic satellite navigation network -- previously restricted to the military and government -- to commercial use, officials say.

Beidou, named for the Chinese word for the Big Dipper constellation, is a competitor to the United States' Global Positioning System and aims to have a 70 percent to 80 percent share of the Chinese location services market by 2020, a Beidou spokesman told the BBC.

The China Satellite Navigation Office said the service, now opened to commercial use in the Asia-Pacific region, would be available across the globe by 2020.

Beidou can pinpoint a user's location to within 33 feet, officials said.

The system has six satellites already in orbit, with 40 more planned during the next decade.

Beidou is one of a number of alternatives to GPS. Russia is developing its Glonass system for both civilian and military use while the European Union is working on its own Galileo network.