20-A. Power to purchase redeemable stock at a premium
(1) A trustee may invest in any of the securities mentioned or referred to in Section 20, notwithstanding that -the same may be redeemable and that the price exceeds the redemption value:
Provided that a trustee may not purchase at a price exceeding its redemption value any security mentioned or referred to in clauses (c) and (d) of Section 20 which is liable to be redeemed within fifteen years of the date of purchase at par or at some other fixed rate, or purchase any such security as it mentioned or referred to in the said clause which is liable to be redeemed at par or at some other fixed rate at a price exceeding fifteen per centum above par or such other fixed rate.
(2) A trustee may retain until redemption any redeemable stock, fund or security which may have been purchased in accordance with this section.