BRUSSELS, Belgium -- The European Union has warned the US Federal Communications Commission that it risks violating an international agreement because of its plan for protecting US telecommunications carriers from stiff foreign competition. In a stern open letter, the Delegation of the European Commission, a branch of the European Union, said language in the US agency's "Notice on Proposed Rule-Making on Foreign Participation" was too broad and vague concerning the conditions under which foreign service providers could be refused a license to operate within the US. The letter read: "The European Community and its member states are concerned that ... the [Federal Communications Commission] would maintain the right to deny access to the US market for applicants from [World Trade Organization] member countries, on the grounds of unclear and broad concepts such as 'public interest factors' or 'very high risk to competition.' " This language, the European Commission said, violated the aim and spirit of the World Trade Organization agreement and the General Agreement on Trade in Services. The letter comes six months after 68 countries adopted the agreement, which sought to open up the world's telecommunications services markets and to stimulate international growth in the industry. An official with the commission declined to comment on the European Union's letter, saying only that it will be taken into consideration before the proposed rules are enacted.