(a) Amendments or supplements to any pleading (complaint, Order of Investigation and Hearing, counterclaim, crossclaim, third-party complaint, and answers thereto) will be permitted or rejected, either in the discretion of the Commission or presiding officer. No amendment will be allowed that would broaden the issues, without opportunity to reply to such amended pleading and to prepare for the broadened issues. The presiding officer may direct a party to state its case more fully and in more detail by way of amendment.

(b) A response to an amended pleading must be filed and served in conformity with the requirements of subpart H and §502.69 of this part, unless the Commission or the presiding officer directs otherwise. Amendments or supplements allowed prior to hearing will be served in the same manner as the original pleading, except that the presiding officer may authorize the service of amended complaints directly by the parties rather than by the Secretary of the Commission.

(c) Whenever by the rules in this part a pleading is required to be verified, the amendment or supplement must also be verified. [Rule 66.]