Article 53U.K.Replacement and assignment
1.Any form of security may be replaced by another.
However, the agreement of the competent authority shall be required in the following cases:
(a)where the original security has been forfeited but not yet realised; or
(b)where the replacement security is of a type listed in Article 51(2).
2.A block security may be replaced by another block security on condition that the new block security covers at least that part of the original block security assigned at the time of replacement to ensure fulfilment of one or more obligations still outstanding.
3.As soon as part of a block security is assigned to a particular obligation, the balance of the block security remaining shall be noted.