Each agency shall prescribe by rule the form for petition requesting the adoption, amendment or repeal of a rule and the procedure for submission, consideration, and disposition thereof. Within 60 days after submission of a petition, the agency either shall deny the petition in writing on the merits, stating its reasons for the denial, or initiate rule-making proceedings in accordance with Section 41-22-5; provided, however, an agency which has its next regularly scheduled meeting beyond said 60-day period, may by written notice extend said period for not more than 30 days during which it shall deny or initiate rule-making proceedings.