(1) An investment firm shall not enter into arrangements for securities financing transactions in respect of client financial instruments held by the investment firm on behalf of a client, or otherwise use such client financial instruments for its own account or the account of another client of the investment firm, unless the following condition is met:
(a) the investment firm has received written confirmation from the client, of either the counterparty credit ratings acceptable to the client or that the client does not wish to specify such rating.