Upon the termination by expiration, cancellation or otherwise, of a
policy of insurance issued under the provisions of law and these
regulations, or the revocation or termination of the privilege of self-
insurance granted by the Office, all certificates of compliance issued
on the basis of such insurance or self-insurance shall be void and shall
be returned by the employer to the district director issuing them with a
statement of the reason for such return. An employer holding certificate
of compliance under an insurance policy which has expired, pending
renewal of such insurance need not return such certificate of compliance
if such expired insurance is promptly replaced. An employer who has
secured renewal of insurance upon the expiration of policy under said
Act or whose self-insurance thereunder is reauthorized without a break
in the continuity thereof need not return an expired certificate of
compliance.