A demerger is a form of corporate restructuring in which the entity's business operations are segregated into one or more components. It is the converse of a merger or acquisition.
A demerger can take place through a spin-off by distributing or transferring the shares in a subsidiary holding the business to company shareholders carrying out the demerger. The demerger can also occur by transferring the relevant business to a new company or business to which then that company's shareholders are issued shares of.