BEIJING » China’s online population soared to 485 million as of the end of June as use of mobile phones to surf the Web spreads, an industry group reported Tuesday.

The number of Chinese Web users, already by far the world’s biggest, rose by 15.5 percent over a year earlier, according to the government-sanctioned China Internet Network Information Center.

China’s communist government promotes Internet use for business and education but tries to block access to material it considers subversive or pornographic.

The number of people who use mobile phones to surf the Web rose to 318 million, or about 65 percent of the total, CNNIC said. That was up 14.8 percent from a year earlier.

The overall growth rate was down slightly from 2010, when the Internet population grew by 19 percent.

China’s rise in Web use has been driven by rapid economic growth that the World Bank forecasts could reach 9.3 percent this year.