The holders of units in a Unit Trust can be individuals, companies or discretionary trusts.
The Unit Trust will be constituted by a trust deed which is “settled” by a trustee. Most commonly the trustee of a Unit Trust engaged in a business activity will be a company. The Unit Trust Deed is the equivalent of a company constitution.
As in the case of a company, the relationship, entitlements and duties of Unit Holders is better recorded in a Unit Holder Agreement (like a Shareholder Agreement) than in the Unit Trust deed itself.
That said, many of the features of a Shareholder Agreement can be imported without change into a Unit Holder Agreement, including those relating to management decisions, transfer of units, pre-emption in the event of death or TPD etc.