"Control shall be constituted by rights, contracts or any other means which, either separately or in combination and having regard to the considerations of fact or law involved, confer the possibility of exercising decisive influence on an undertaking, in particular by: (a) ownership or the right to use all or part of the assets of an undertaking; (b) rights or contracts which confer decisive influence on the composition, voting or decisions of the organs of an undertaking. Control is acquired by persons or undertakings which: (a) are holders of the rights or entitled to rights under the contracts concerned; or (b) while not being holders of such rights or entitled to rights under such contracts, have the power to exercise the rights deriving therefrom." © Article 3 of the Council Regulation (EC) No 139/2004 of 20 January 2004 on the control of concentrations between undertakings
See also Joint control and Joint venture