LUXEMBOURG (Dow Jones)--Europe's highest court Tuesday upheld a Europe-wide law forcing mobile operators to cut the rates they charge for using a mobile phone abroad. Four of Europe's largest mobile telecom operators--Vodafone Group PLC (VOD), Telefonica SA's (TEF) O2, Deutsche Telekom AG's (DT) T-Mobile and France Telecom's (FTE) Orange--challenged the legality of the European Union's roaming regulation, passed in 2007, which imposed a substantial reduction in charges on the operators. "The roaming regulation is valid. The community had the right to impose caps on the prices charged by mobile telephone operators for roaming calls in the interest of the internal market," the European Court of Justice said in a statement. -By Mike Gordon, Dow Jones Newswires; +352 691 180 766; [email protected] (END) Dow Jones Newswires June 08, 2010 03:54 ET (07:54 GMT)