“enterprise” means a person or a department of the Government, who or which is, or has been, engaged in any activity, relating to the production, storage, supply, distribution, acquisition or control of articles or goods, or the provision of services, of any kind, or in investment, or in the business of acquiring, holding, underwriting or dealing with shares, debentures or other securities of any other body, corporate, either directly or through one or more of its units or divisions or subsidiaries, whether such unit or division or subsidiary is located at the same place where the enterprise is located or at a different place or at different places, but does not include any activity of the Government relatable to the sovereign functions of the Government including all activities carried on by the departments of the Central Government dealing with atomic energy, currency, defence and space.”