DUTY TO SERVE CERTAIN USERS EXTINGUISHED.

(a) A gas utility that provides gas to a customer does not have an obligation to serve the customer or to maintain the gas supply or physical capacity to serve the customer if the customer: (1) is a transportation, industrial, commercial, or other similar large-volume contract customer; (2) is an end-use customer of the gas utility; (3) reduces or ceases the purchase of natural gas or natural gas service from the gas utility; and (4) purchases natural gas or natural gas service from another supplier or purchases an alternate form of energy. (b) Subsection (a) does not apply to the extent that: (1) the customer continues to purchase natural gas or natural gas service of any class from the gas utility; or (2) the gas utility has a written contract to provide natural gas or natural gas service of any class to the customer. (c) This section does not prevent the railroad commission from requiring a gas utility to comply with an order of the railroad commission in apportioning gas under a curtailment plan and order. (d) Notwithstanding Subsection (a), a gas utility that has provided gas to a commercial customer is obligated to serve that customer if the gas utility has a sufficient gas supply and physical capacity to do so without reducing service to its other customers.