Written agreements.

(a) A reinsurance agreement or amendment to an agreement may not be used to reduce liability or to establish an asset in a financial statement filed with the Department, unless the agreement, amendment or a binding letter of intent has been executed by both parties no later than the ‘‘as of date’’ of the financial statement.

(b) In the case of a letter of intent, a reinsurance agreement or an amendment to a reinsurance agreement shall be executed within a reasonable period of time, not exceeding 90 days from the execution date of the letter of intent, for credit to be granted for the reinsurance ceded.

(c) The reinsurance agreement shall contain provisions which provide the following:

(1) The agreement shall constitute the entire agreement between the parties with respect to the business being reinsured thereunder and that there are no understandings between the parties other than as expressed in the agreement.

(2) A change or modification to the agreement shall be void unless made by amendment to the agreement and signed by both parties.