21.7.98 Official Journal of the European Communities L 204/1 (Acts whose publication is obligatory) DIRECTIVE 98/30/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 22 June 1998 concerning common rules for the internal market in natural gas THE EUROPEAN PARLIAMENT AND THE COUNCIL OF THE EUROPEAN UNION, Having regard to the Treaty establishing the European Community, and in particular Articles 57(2), 66 and 100a thereof, Having regard to the proposal from the Commission (1), Having regard to the opinion of the Economic and Social Committee (2), Acting in accordance with the procedure laid down in Article 189b of the Treaty (3), (1)  Whereas, according to Article 7a of the Treaty, the internal market shall comprise an area without internal frontiers in which the free movement of goods, persons, services and capital is ensured; whereas it is important to adopt measures to continue the completion of the internal market; (2)  Whereas, under Article 7c of the Treaty, differences in development of certain economies have to be taken into account, but derogations must be of a temporary nature and cause the least possible disturbance to the functioning of the common market; (3)  Whereas the establishment of a competitive natural gas market is an important element of the completion of the internal energy market; (1) O] C 65, 14.3.1992, p. 14, and O] C 123, 4.5.1994, p. 26. () O] C 73, 15.3.1993, p. 31, and O] C 195, 18.7.1994, p. 82. (*) Opinion of the European Parliament of 17 November 1993 (OJ C 329, 6.12.1993, p. 182), Council Common Position (EC) No 17/98 of 12 February 1998 (O] C 91, 26.3.1998, p. 46) and Decision of the European Parliament of 30 April 1998 (OJ C 152, 18.5.1998). Council Decision of 11 May 1998. (4)  Whereas Council Directive 91/296/EEC of 31 May 1991 on the transit of natural gas through grids (*) and Council Directive 90/377/EEC of 29 June 1990 concerning a Community procedure to improve the transparency of gas and electricity prices charged to industrial end-users (°) constitute a first phase of the completion of the internal market in natural gas; (5) Whereas it is now necessary to take further measures with a view to establishing the internal market in natural gas; (6)  Whereas the provisions of this Directive should not affect the full application of the Treaty, in particular the provisions concerning the free movement of goods in the internal market and the rules on competition, and do not affect the powers of the Commission under the Treaty; (7)  Whereas the internal market in natural gas needs to be established gradually, in order to enable the industry to adjust in a flexible and ordered manner to its new environment and in order to take account of the different market structures in the Member States; (8)  Whereas the establishment of the internal market in the natural gas sector should favour the interconnection and interoperability of systems, for example through compatible qualities of gas; (9)  Whereas a certain number of common rules should be established for the organisation and operation of the natural gas sector; whereas, in accordance with the principle of subsidiarity, these rules are no more than general principles providing for a framework, the detailed implementation of which should be left to Member States, thus allowing each Member State to maintain or choose the () OJ L 147, 12.6.1991, p. 37. Directive as last amended by Directive 95/49/EC (O] L 233, 30.9.1995, p. 86). (’) OJ L 185, 17.7.1990, p. 16. Directive as last amended by the 1994 Act of Accession.