This article considers current European Union and Ukraine’s wholesale natural gas market in light of regulatory measures that had been enacted and/or implemented with respect to its organization and functioning. The analysis points to three major goals EU’s energy sector regulation is geared to achieve: 1) economic (i.e. procompetitive support); 2) energy security; and 3) social goals. As such, the EU wholesale energy market can be regarded as a regulatory instrument. Ukraine assumed the obligation to implement EU legislation in the field of energy sector regulation (Energy Community acquis communautaire): Act of Ukraine No. 329-VIII of 9 April 2015 on natural gas market implements fundamental principles of the third energy package in the area of organization and functioning of the wholesale natural gas market. However, for Ukraine’s wholesale energy market to assume characteristics of a regulatory instrument akin to the EU market, further implementation of EU regulation 1227/2011 (REMIT) and, to some extent, implementation of the fourth energy package is needed. Part 2 assesses current efforts and discusses regulatory requirements that Ukraine faces if it wants to successfully incorporate EU gas market principles within its natural gas market.