You will need to provide much more information about the 4 different businesses, their expected valuations, shareholders personal circumstances (such as are the shareholders able to avail of early retirement relief, what succession plans do they have, can they avail of previous capital losses etc) in order to receive useful advice.
Depending on the factual matrix, the solution might be a Members Voluntary Liquidation with a distribution of the assets in specie (which would avoid stamp duty) or "hiving" one business down to a subsidiary, or a sale of one business to a shareholder etc
Jim Stafford