The European Commission will urge countries to demand that online gambling advertisements display warning messages like cigarette packets, according to a draft document seen by Reuters.

The EU executive will make its recommendation to improve controls of the 10.5 billion-euro ($14.3 billion) online gambling industry next week, focusing on advertisements to tackle compulsive gambling.

Although the recommendation is not legally binding, it could prompt European countries to tighten rules in the area.

Growing at a rate of 15 percent a year, online gambling is the fastest growing service activity in the EU, with 6.8 million users in 2011, according to the European Commission.

The warning signs that online gambling companies will be urged to feature in their advertisements include the chances of winning and losing, information on the risk of becoming addicted to gambling and assistance for compulsive gambling.

The EU is also proposing a ban on online gambling firms sponsoring events aimed at minors.

Online gambling exchange Betfair, as well as traditional bookmakers such as William Hill, have already come under the scrutiny of governments and have bet heavily on the World Cup to boost revenues.

(Editing by Andrew Roche)