End-user generated revenues from mobile games will reach nearly $10bn by 2009, according to a new report.

Analyst firm Juniper Research said that the revenues will be driven by the increasing popularity of casual gaming, combined with more gaming-friendly handsets offering high-quality 3D graphics.

"Game downloads have already overtaken ring-tones in a number of western European markets, while mobile handsets are now the de facto games console in many developing countries," said report author Dr Windsor Holden.

More than 460 million mobile users are expected to download games by 2009, representing a twofold increase on the current number.

Much of this growth is expected in emerging markets such as the Indian sub-continent, where the number of users will rise from 10 million in 2007 to nearly 40 million in 2009.

However, the report warned that the high cost of browsing and downloading services and content in many countries, combined with opaque pricing structures, continues to act as major stumbling blocks to service adoption.

Juniper also warned that that more needs to be done to widen the mobile gaming demographic, although the firm did note an increasing number of products targeting female gamers.

"Essentially, the proportion of leading titles focusing on action and adventure has not altered discernibly over the past two years," said Dr Holden.

"While these are popular within the traditional gaming demographic, there is a major opportunity to attract casual gamers by enhancing a portfolio mix with more titles from alternative genres."

China and the Far East will remain the largest regional markets for mobile games throughout the period covered by the report, with predicted revenues of $5.7bn by 2012.

Worldwide revenues from in-game advertising are expected to grow from $90m in 2007 to more than $1.2bn in 2012.

As well as diversifying the game content to appeal to a wider audience, the report suggests that operators and publishers should expand the number of games they offer on a free trial basis.

By removing the entry price barrier, Juniper believes that a greater number of consumers will play the game and ultimately convert to being paid customers.