Energy legislation has become one of the important segments on the path toward membership in the European Union, which includes an obligation to introduce appropriate adjustments to European energy legislation and standards of the internal energy market.
European Parliament and Council Directives 2003/55/EC of 26 June 2003 on common rules for the internal market in natural gas and 2004/67/EC of 26 April 2004 concerning measures to safeguard security of natural gas supply were the basic guidelines for amended legislation and all by-laws. Natural gas market opening ensures all customers a free choice of supplier and all suppliers the opportunity to conclude contracts with new customers. The basic condition for the market opening is non-discriminatory, fair and transparent access to the gas transmission and distribution network.
New energy laws has governed the relations between the market participants on the gas market. The Energy Act (Official Gazette 68/01,177/04, 76/07, 152/08 & 127/10) is the fundamental law whilst relations between market participants are established and regulated trough The Gas Market Act (Official Gazette 40/07, 152/08, 83/09, 91/11), The Act on the Regulation of Energy Activities (Official Gazette 177/04 & 76/07), Rules on the Natural Gas Market Organization (Official Gazette 126/10 & 128/11) and General Conditions for the Natural Gas Supply (Official Gazette 42/09). Thus Republic of Croatia created the preconditions for a fully open gas market.
Source Serbia-energy.com