The European Commission will detail its plans to regulate the cost of international roaming for mobile phone users at a meeting in Brussels on Tuesday."The objective is to promote competition and to ensure that consumers are not punished for crossing a border," said Martin Selmayr, a spokesman for Viviane Reding, European Commissioner for Information Society and Media.Reding will reveal the plans at a meeting with Kip Meek, the chairman of the European Regulators Group. The announcement, originally scheduled for April, follows a six-week public inquiry into the roaming charges, which is set to close Wednesday night.Since the Commission made clear that it is closely monitoring the cost of roaming, some European network operators have announced cuts in their roaming charges. Three network operators in Ireland, for example, have abolished roaming fees for customers travelling to Northern Ireland or the rest of the U.K.The abolition of border controls between many European Union member states means that for many Europeans, "The only way you find out today that you have crossed a border is when your mobile phone connects to a foreign network," Selmayr said.The regulations will affect roaming charges for customers of one EU network operator roaming on a network in another of the EU's 25 member states, he said.To back up its regulatory proposal, the Commission has studied the economic impact on network operators. "Some say 10% to 15% of revenue comes from roaming," Selmayr said. "Everybody is using speculative figures at the moment," he added, saying that the Commission would publish its own estimates next week.The GSM Association will file its contribution to the public inquiry later Wednesday, according to association spokesman David Pringle. The association, which brings together mobile phone operators, would not disclose details of its submission ahead of time.On Tuesday, the Commission will also update a Web site where it tracks international roaming charges to show how prices have evolved since last year."That will allow everybody to judge whether prices have come down or not," Selmayr said.Members of the public can still submit comments about roaming charges Wednesday by clicking here.