(E) The filing of, and the consent and approval of the Commission for, any assignment, transfer, lease, mortgage, purchase, sale, merger, consolidation, contract or other transaction by an electric or gas public utility with gross revenues in all jurisdictions of $250,000,000 or more annually involving a sale price or annual consideration in an amount of $5,000,000 or less shall not be required. The Commission shall also have the authority, on petition by an electric or gas public utility with gross revenues in all jurisdictions of $250,000,000 or more annually, to establish by order higher thresholds than the foregoing for the requirement of approval of transactions by the Commission pursuant to this Section for the electric or gas public utility, but no greater than 1% of the electric or gas public utility's average total gross utility plant in service in the case of sale, assignment or acquisition of property, or 2.5% of the electric or gas public utility's total revenue in the case of other sales price or annual consideration, in each case based on the preceding calendar year, and subject to the power of the Commission, after notice and hearing, to further revise those thresholds at a later date. In addition to the foregoing, the Commission shall have power by general rules applicable alike to all electric and gas public utilities affected thereby to waive the filing and necessity for approval of the following: (a) sales of property involving a consideration of $100,000 or less for electric and gas utilities with gross revenues in all jurisdictions of less than $250,000,000 annually; (b) leases, easements and licenses involving a consideration or rental of not more than $10,000 per year for electric and gas utilities with gross revenues in all jurisdictions of less than $250,000,000 annually; (c) leases of office building space not required by the electric or gas public utility in rendering service to the public; (d) the temporary leasing, lending or interchanging of equipment in the ordinary course of business or in the case of an emergency; and (e) purchase-money mortgages given by an electric or gas public utility in connection with the purchase of tangible personal property where the total obligation to be secured shall be payable within a period of one year or less. However, if the Commission, after a hearing, finds that any electric or gas public utility is abusing or has abused such general rule and thereby is evading compliance with the standard established herein, the Commission shall have power to require such electric or gas public utility to thereafter file and receive the Commission's approval upon all such transactions as described in this Section and not exempted pursuant to the first sentence of this paragraph or to subsection (g) of Section 16-111 of this Act, but such general rule shall remain in full force and effect as to all other electric and gas public utilities. Every assignment, transfer, lease, mortgage, sale or other disposition or encumbrance of the whole or any part of the franchises, licenses, permits, plant, equipment, business or other property of any public utility, or any merger or consolidation thereof, and every contract, purchase of stock, or other transaction referred to in this Section and not exempted in accordance with the provisions of the immediately preceding paragraph of this Section, made otherwise than in accordance with an order of the Commission authorizing the same, except as provided in this Section, shall be void. The provisions of this Section shall not apply to any transactions by or with a political subdivision or municipal corporation of this State.