BEIJING, Aug. 21 (AP) -- Chinese regulators will soon announce a digital TV standard for the world's biggest television market, a state news agency reported Monday.

The system will apply to terrestrial, satellite and cable broadcasts in China, the Xinhua News Agency said, citing Wang Xiaojie, director of the technology department of State Administration of Radio, Film and Television.

China has about 400 million television viewers, according to industry estimates, and already is one of the one of the leading producers of digital television sets.

The government said earlier that it would start rolling out digital television this year.

China already has 4.13 million households that receive digital pay-TV channels, and companies that serve them will be required to switch to the new standard, Xinhua said.

China has more than 120 licensed pay television channels, according to the government. It said earlier that some 30 million households were expected to sign up for digital pay channels in coming years.

China has been testing digital cable TV since 2003 in 49 areas, with more than 1 million subscribers, according to earlier news reports.