In each instance of the issuance of general obligation or revenue bonds by the State of Oklahoma or any political subdivision thereof, or by any trust or other agency on behalf of any such entity, the issuer may be represented by bond counsel. Such bond counsel is prohibited from representing or receiving compensation from underwriters or the purchasers of the bonds for the same issuance. However, said opinions by bond counsel may be addressed to and furnished to the underwriters and purchasers as long as no additional compensation is paid.