[en] Until 1989, despite the partially disintegrated organization of the British electricity supply industry (ESI) and the attempt of the Energy Act of 1983 to pull down entrance barriers to the power generation business, ESI operated like an integrated monopoly. Between 1989 and 1990, ESI has been subjected to a reorganization process and transfer to the private sector with the declared aim of improving short and long run micro-economic efficiency. For this purpose, the attempt of introducing competition in the phases of the production process where possible and of regulating those which are structurally non competitive, has been made. The new configuration of ESI in terms of organizational structure, property regime and regulatory system is analyzed. Areas of improvement of the regulatory system and delayed key decisions of the public operator, are identified. However, any evaluation of the process as a whole can only relate to a minor part of the present situation; thus it subtends a scenary for the future, where the role of the regulatory authority is crucial