Along with aviation and telecommunications, the gas supply chain has proved to be one of the paradigmatic factors in the great transformation in regulated industry law that has characterized recent decades. Liberalization in the gas market has taken two primary legal forms: (1) removal of entry barriers in competitive sectors and (2) regulation of infrastructure sectors through unbundling (economic separation of competitive and infrastructure sectors) and open access (requiring gas infrastructure owners and operators to allow competitors to access their facilities on commercial terms comparable to those that would apply in a competitive market).This book will focus on the latter legal form.