Natural gas is a key source of energy for OECD countries, both in its own right and as an input into the production of electricity. Regulatory reform in this sector shares both important similarities and important differences with regulatory reform in other network industries. Like other network industries, regulatory reform in natural gas involves promoting competition in the competitive segments of the industry (particularly competition between gas producers), the development of a robust regime for access to the remaining essential facilities, and structural separation between the competitive and non-competitive segments of the industry. OECD countries have pursued each of these steps, licensing independent producers, pricing access to pipeline infrastructure and separating gas production from transportation (although long-term take-or-pay contracts make this last reform more difficult). Unlike other network industries, however, the structure of the industry varies widely from country to country according to the number of domestic gas producers, the geographic location of pipelines and the uses to which natural gas is put. Countries which rely primarily on imported gas have less to gain from domestic reform and much to gain from reform in producing countries. As OECD gas sources diminish and reliance on imports increases, regulatory reform in natural gas will increasingly become an issue for international trade.