If for any reason the market value of securities of an insurer held on deposit in this State as required under this Title falls below the required amount, the insurer shall promptly deposit other or additional assets eligible for deposit sufficient to cure the deficiency. If the insurer has failed to cure the deficiency within 20 days after receipt of notice thereof by registered mail from the superintendent, the superintendent shall forthwith revoke the insurer's certificate of authority.   [PL 1969, c. 132, §1 (NEW); PL 1973, c. 585, §12 (AMD).]