China plans to implement a five year program advocating clean online games, starting next year, an official from the General Administration of Press and Publication told an industry conference Wednesday.

Earlier this week, GAPP issued a notice warning against the illegal release of online games and declaring stricter control over the approval process. The notice criticized the release of pornographic and violent games by some companies on the Internet.

The China Green Online Games Publishing Program will be launched this year and the implementation begun next year, the Xinhua news agency said, citing remarks by Sun Shoushan, vice director of the GAPP, at an industry conference in Shanghai.

Some companies provide unhealthy and persuasive contents in online games for players, especially the young ones, so as to attract players and make unlawful profits, Sun was quoted as saying.

The online game industry in China is expected to grow by between 30 percent and 50 percent this year, with sales revenue of 24 billion to 27 billion yuan ($3.51 billion - $3.95 billion), according to the official.

China has about 200 million online game players.

The Chinese government has closed hundreds of websites in an ongoing crackdown on online porn and vulgar content that in some cases has netted dissident sites. The government backed down on a plan to require that Green Dam filter software be pre-installed on all new computers.

(Reporting by Lucy Hornby)