Section 15
SEC. 15. The grantee herein may, with the prior approval of the Public Utility Commission, sell, lease, give, grant, convey, or assign the usufruct of this franchise and all property and rights acquired thereunder to any person or corporation: Provided, That for the purpose of the sale, lease, donation, granting, or transfer, it shall be necessary to file in the office of the Secretary of Commerce and Communications an agreement in writing by which the purchaser, lessee, donee or assignee shall bind himself to comply with all the terms and conditions imposed upon the grantee by this franchise, and to accept the same subject to all existing terms and conditions.