The European Union today warned carriers in its member states that it would start regulating the roaming rates for data and messaging in the region without voluntary price drops. While not saying what would dictate the regulation, Commissioner Viviane Reding explains that the government body will start posting Europe-wide prices in the next two weeks and will likely demand that most prices be regulated lower if not dropped voluntarily.

The changes follow similar practices for call roaming in Europe and are meant to curb what some believe is deliberate overcharging for mobile services, which carriers are often accused of using to boost profits in place of or in addition to higher costs for domestic users.

Officials from both France and Italy say they support the measure, while those from Belgium and other countries are primarily supportive of regulations for messages but believe it may be too early to regulate data rates, which are more expensive to maintain.

T-Mobile, Vodafone and other Europe-centric carriers under the GSM Association defend their pricing by claiming that the industry is both growing quickly and already dropping prices to match: the number of users on 3G-based UMTS or HSPA networks doubled to 112 million continent-wide between April 2007 and 2008 while rates themselves in some areas dropped to less than that of DSL or other hardwired services.

The issue comes as 3G traffic is likely to increase sharply with the release of the iPhone 3G in multiple European countries next month; data use among owners of the initial phone is known to be much higher than average for other devices.