1.Member States shall ensure that the eligible customers comprise:
(a)until 1 July 2004, eligible customers as specified in Article 18 of 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(1). Member States shall publish, by 31 January each year, the criteria for the definition of those eligible customers;
(b)from 1 July 2004, all non-household customers;
(c)from 1 July 2007, all customers.
2.To avoid imbalance in the opening of the gas markets:
(a)contracts for the supply with an eligible customer in the system of another Member State shall not be prohibited if the customer is eligible in both systems involved; and
(b)where transactions as described in point (a) are refused because the customer is eligible in only one of the two systems, the Commission may, taking into account the situation in the market and the common interest, oblige the refusing party to execute the requested supply, at the request of one of the Member States of the two systems.