(a) A petitioner may withdraw or narrow a petition for forbearance without approval of the Commission by filing a notice of full or partial withdrawal at any time prior to the end of the tenth business day after the due date for reply comments announced in the public notice.

(b) Except as provided in paragraph (a) of this section, a petition for forbearance may be withdrawn, or narrowed so significantly as to amount to a withdrawal of a large portion of the forbearance relief originally requested by the petitioner, only with approval of the Commission.