Also known as a spin-off, a demerger describes the segregation of business activities carried on by a company or group into separate companies which are then usually owned by the same shareholders. A partition demerger results in a change of control as well as the segregation of the demerged asset from the group.

For an overview of demergers, including the reasons for implementing a demerger and the different structures that may be used to achieve a demerger, see Practice note, Demergers. For the tax implications of demergers, see Practice note, Demergers: tax overview.