The verified petition of one or more owners of property affected by the proposed amendment, which petition shall be filed with the planning commission and it shall be accompanied by the required filing fee, no part of which shall be returnable to the petitioner;

Resolution of intention by the board of supervisors;

Resolution of intention by the planning commission.

Upon receipt of such report from the planning commission, the board of supervisors shall set the matter for public hearing, and shall give notice thereof by one publication in a newspaper of general circulation within the county at least ten days prior to such hearing. After conclusion of the hearing, the board may adopt the proposed amendment or any part thereof in such form as said board may deem advisable.

The decision of the board shall be rendered within ninety days after the receipt of a report and recommendation from the planning commission. Upon the consent of the planning commission, any petition for an amendment may be withdrawn upon the written application of a majority of all the persons who signed such petition. The board or the planning commission, as the case may be, may by resolution abandon any proceedings for an amendment initiated by its own resolution of intention; provided, that such abandonment may be made only when such proceedings are before such body for consideration and provided that any hearing of which public notice has been given shall be held.