Court of Justice of the European Communities — Costs — Costs of expert examination ordered by Court into economic aspects of railway tariffs — Rules of Procedure, Articles 49 (1) and 73 (a).

International organization — European Coal and Steel Community — Decisions of High Authority — Appeal by enterprises for annulment of decision concerning rail tariffs contained in letter from Authority to Government of member State — Whether enterprises have sufficient interest to bring appeal — Violation of Treaty, Article 70 — Element of subsidy in rail tariffs — Whether tariffs also discriminatory within Article 4 — Powers of High Authority to grant time-limits for modification of tariffs under Convention containing Transitional Provisions — Competence of Authority to interfere in transport matters — Requirement of discrimination as condition of such competence.