(a) As used in this section the terms “affiliated” and “affiliate” shall have the same meaning as set forth in section 337.7¹, providing however, that control shall be presumed to exist if any person, directly or indirectly, owns, controls, holds with power to vote, or holds shares representing eighty per centum (80%) or more of the voting power of any other person.

(b) Nothing contained in sections 319 or 319.1² shall apply to reinsurance agreements between or among affiliates covering all or substantially all of one or more lines of insurance of an affiliated domestic or foreign stock or mutual insurance company, association or exchange, provided that the amount of net written premium retained and the amount of the reinsurance and retrocession assumed by any affiliate participating agreement shall not be unreasonably large in relationship to its policyholders' surplus.