Variation of employee unit-based benefits allowed with safeguards and required unitholder approval, including controlled repricing. Regulation 17M authorises the investment manager to vary terms of a unit based employee benefit scheme not yet exercised by employees so long as changes are not prejudicial to employees; unitholder approval is required per regulation 22(5) except where changes are needed to meet legal or regulatory obligations. Notices and resolutions must disclose full details, rationale, affected employees and information as per Part C of Schedule IX or Board directions. The investment manager may reprice unexercised options if unit price decline renders the scheme unattractive, subject to non-detriment to employees and unitholder approval.