(c)invest, otherwise than in trust securities, [the amount of compensation received by the company in respect of the compulsory acquisition, after the commencement of this Act] [ Substituted by Act 65 of 1960, Section 98, for certain words (w.e.f. 28.12.1960).], of any such undertaking as is referred to in clause (a), or of any premises or properties used for any such undertaking and without which it cannot be carried on or can be carried on only with difficulty or only after a considerable time;