(a) Any interested person or organization wishing to participate as amicus curiae in the proceeding shall file a petition before the commencement of the hearing. Such petition shall concisely state the petitioner's interest in the hearing and who will represent petitioner.

(b) The administrative law judge will grant the petition if he finds that the petitioner has an interest in the proceedings and may contribute materially to the disposition of the proceedings. The administrative law judge shall give the petitioner written notice of the decision on his petition.

(c) An amicus curiae is not a party and may not introduce evidence at a hearing but may only participate as provided in paragraph (d) of this section.

(d) An amicus curiae may submit a written statement of position to the administrative law judge at any time prior to the beginning of a hearing, and shall serve a copy on each party. He may also file a brief or written statement on each occasion a decision is to be made or a prior decision is subject to review. His brief or written statement shall be filed and served on each party within the time limits applicable to the party whose position he deems himself to support; or if he does not deem himself to support the position of any party, within the longest time limit applicable to any party at that particular stage of the proceedings.

(e) When all parties have completed their initial examination of a witness, any amicus curiae may request the administrative law judge to propound specific questions to the witness. The administrative law judge, in his discretion, may grant any such request if he believes the proposed additional testimony may assist materially in elucidating factual matters at issue between the parties and will not expand the issues.