SHANGHAI - The pace of growth of China's online gaming industry slowed in 2009, growing 30.2 percent to 27.1 billion yuan ($3.97 billion) over the previous year, according to data from research firm iResearch.

The top game operators of 2009 by market share were Tencent Holdings, Shanda Games and the Beijing-based company said.

The number of active online gamers totaled 60 million to 70 million in 2009, about a fifth of China's total Internet population.

China's online gaming revenue, which has seen explosive growth over the past few years, is expected to more than double in the next three years as companies take advantage of increased Internet penetration and rapidly developing sectors such as online social games and online mobile games.

(Reporting by Melanie Lee; Editing by Chris Lewis)