delivered the opinion of the Court.
Thе question presented in this case is whether under the Natural Gas Act, 52 Stat. 821, 15 U. S. C. § 717
et seq.,
a regulated natural gas company furnishing gas
In June 1953 United, without the consent of Mobile, filed new schedules with the Commission which purported to increase the rate on gas for resale to Ideal to 14.5 cents per MCF, a rate more closely approximating that for other gas furnished to Mobile by United. Claiming that United could not thus unilaterally сhange the contract rate, Mobile petitioned the Commission to reject United’s filing. The Commission denied the petition, holding that under § 4 (d) of the Act the new rate, being a non-sus-pendible industrial rate, automatically became effective 30 days after filing and would remain in effect unless and until the Commission should, after investigation
The question presented is solely one of the proper interpretation of the Natural Gas Act, there being no claim that the statute, if interpreted to permit a natural gas company unilaterally to change its contracts, would be
In construing the Act, we should bear in mind that it evinces no purpose to abrogate private rate contracts as such. To the contrary, by requiring contracts to be filed with the Commission, the Act expressly recognizes that rates to particular customers may be set by individual contracts. In this respect, the Act is in marked contrast to the Interstate Commerce Act, which in effect precludes private rate agreements by its requirement that the rates to all shippers be uniform, a requirement which made unnecessary any provision for filing contracts. See
Armour Packing Co.
v.
United States,
The provision of the Natural Gas Act directly in issue here is § 4 (d), which provides that “no change shall be made by any nаtural-gas company in any such [filed] rate ... or contract . . . except after thirty days’ notice to the Commission,” which notice is to be given by filing new schedules showing the changes and the time they are to go into effect. It is argued that this provision authorizes a natural gas company to change its rate contracts simply by filing a new schedule of rates, to go into effect in no less than thirty days. On its face, however, § 4 (d) is simply a prohibition, not a grant of power. It does not purport to say what is effective to change a contract, any more thаn § 4 (c) purports to define what constitutes a “contract” that may be filed with the Commission. The section says only that a change
cannot
be made without the proper notice to the Commission; it does not say under what circumstances a change
can
be made. Absent the Act, a unilateral announcement of a change to a contract would of course be a nullity, and we find no basis in the language of § 4 (d) for inferring that the mere imposition of a filing-and-notice requirement was intended to make effective action which would otherwise be of no effect at all. In short, § 4 (d) on its face indicates no more than that otherwise valid changes cannot be put into effect
It is argued, however, that a different conclusion is compelled when § 4 (d) is read with the other provisions of the Act. Petitioners attempt to characterize the Act as setting up two separate and distinct “procedures” for changing rates: (1) the “hearing and order” procedure of § 5 (a) under which the Commission may determine existing rates to be unreasonable and order changes to be made; and (2) the “filed-rate” procedure of § 4 (d) and (e) under which the natural gas company may initiate changes, in which event the Commission’s only concern is with the reasonableness of the new rate. These are said to be complementary and mutually exclusive procedures, the choice between which — since both expressly relate to changes in “contracts” as well as other rates— depends solely on who is seeking the change and not on whether the rate sought to be changed is embodied in a contract. From this characterization of the procedures, petitioners conclude that when a natural gas company initiates a rate change under § 4 (d) the proceedings are governed exclusively by § 4 (d) and (e), and hence the Commission’s only power is that which it has under § 4 (e) to set aside the new rate if that is found to be unlawful.
The major defect of this argument is that it assumes the answer to the very question in issue — whether natural gas companies are empowered to “initiate” unilateral contract changes under §4 (d). That the so-called “filed-rate” procedure is applicable to changes in contracts as well as other rates proves only that contracts may be changed, not that they may be changed unilaterally. Moreover, the very premise that §§ 4 (d) and (e) and 5 (a) are alternative rate-changing “procedures” is itself
The powers of thе Commission are defined by §§ 4 (e) and 5 (a). The basic power of the Commission is that given it by § 5 (a) to set aside and modify any rate or contract which it determines, after hearing, to be “unjust, unreasonable, unduly discriminatory, or preferential.” This is neither a “rate-making” nor a “rate-changing” procedure. It is simply the power to review rates and contracts made in the first instance by natural gas companies and, if they are determined to be unlawful, to remedy them. Section 5 (a) would of its own force apply to all the rates of a natural gas company, whether long-established or newly changed, but in the latter case the power is further implemented by §4(e). All that § 4 (e) does, however, is to add to this basic power, in the case of a newly changed rate or contract (except “industrial” rates), the further powers (1) to preserve the status quo pending review of the new rate by suspending its operation for a limited period, and (2) thereafter to make its order retroactive, by means of the refund procedure, to the date the change became effective. The scope and purрose of the Commission’s review remain the same— to determine whether the rate fixed by the natural gas company is lawful.
The limitations imposed on natural gas companies are set out in §§ 4 (c) and 4 (d). The basic duties are
The relationship of these sections thus affords no support to petitioners’ characterization of § 4 (d) and (e) as establishing a rate-changing “procedure” — a “proceeding” before the Commission “initiated” by a natural gas company filing a “proposed” change. Section 4 (d) provides not for the filing of “proposals” but for notice to the Commission of any “change . . . made by” a natural gas company, and the change is effected, if at all, not by an order of the Commission but solely by virtue of the natural gas company’s own action. If the purported change is one the natural gas company has the power to make, the “change” is completed upon compliance with the nоtice requirement and the new rate has the same force as any other rate — it can be set aside only upon being found unlawful by the Commission. It is thus no more a “proposed” rate than any other rate, all of which are equally subject to Commission review. Likewise, no “proceeding” is “initiated” by a § 4 (d) filing. A proceeding to review the new rate may be initiated under §4 (e), but, if so, it is initiated by the Commission in the same manner as a proceeding under § 5 (a) to review any other rate, that is, upon complaint or its own motion.
All of the rеlevant provisions of the Act can thus be fully explained as simply defining and implementing the powers of the Commission to review rates set initially by natural ga.s companies, and there is nothing to indicate that they were intended to do more. Admittedly, the Act presumes a capacity in natural gas companies to make rates and contracts and to change them from time to time, but nowhere in the Act is either power defined. The obvious implication is that, except as specifically limited by the Act, the rate-making powers of natural gas сompanies were to be no different from those they would possess in the absence of the Act: to establish
ex parte,
and change at will, the rates offered to prospective customers; or to fix by contract, and change only by mutual agreement, the rate agreed upon with a particular customer. No more is necessary to give full meaning to all the provisions of the Act: consistent with this, § 4 (d) means simply that
no
change — neither a unilateral change to an
ex parte
rate nor an agreed-upon change to a contract — can be made by a natural gas company without the proper nоtice to the Commission. Hence there is nothing in the structure or purpose of the Act from which we can infer the right, not otherwise possessed and nowhere expressly given by the Act,
Our conclusion that the Natural Gas Act does not empower natural gas companies unilaterally to change their contracts fully promotes the purposes of the Act. By preserving the integrity of contracts, it permits the stability of supply arrangements which all agree is essential to the health of the natural gas industry. Conversion by consumers, particularly industrial users, to the use of natural gas may frequently require substantial investments which the consumer would be unwilling to make without long-term commitments from the distributor, and the distributor can hardly make such commitments if its supply contracts are subject to unilateral change by the natural gas company whenever its interests so dictate. The history of the Ideal contract furnishes a case in point. On the other hand, denying to natural gas companies the power unilaterally to change their contracts in no way impairs the regulatory powers of the Commission, for the contracts remain fully subject to the paramount power of the Commission to modify them when necessary in the public interest. The Act thus affords a reasonable accommodation between the conflicting interests of contract stability on the one hand and public regulation on the other.
It may be noted also that this interpretation, while precluding natural gas companies from unilaterally changing their contracts simply because it is in their private interests to do so, dоes not deprive them of an avenue of relief when their interests coincide with the public interest. Section 5 (a) authorizes the Commission to investigate rates not only “upon complaint of any State, municipality, State commission, or gas distributing company” but also “upon its own motion.” Thus, while natural gas companies are understandably not given the same explicit standing to complain of their own contracts
The prior decisions of this Court cited by petitioners as requiring an opposite result are readily distinguishable. In
Armour Packing Co.
v.
United States,
The only two Courts of Appeals that have squarely ruled on this question, those for the District of Columbia and Third Circuits, have concluded that neither the Natural Gas Act,
5
nor the virtually identical provisions of the Federal Power Act
6
authorize unilateral contract changes.
7
The Court of Appeals for the Fifth Circuit, however, although distinguishing its decision on a procedural ground, has indicated a contrary conclusion.
8
The parties have also referred us to numerous state court decisions construing state statutes of varying degrees of similarity to the Natural Gas Act, some holding that unilateral contract changes were authorized
9
and others
From our conclusion that the Natural Gas Act gives a natural gas company no power to change its contracts unilaterally, it follows that the new schedule filed by United was a nullity insofar as it purported to change the rate set by its contract with Mobile and that the contract rate remained the only lawful rate. There can be no doubt of the authority of the Commission to reject the unauthorized filing under its general powers to issue orders “necessary or appropriate tо carry out the provisions of this Act,” § 16, and its failure to do so and its order “permitting” the new rates to become effective were in error. Any amounts paid by Mobile in excess of the contract rates on the basis of the erroneous order of the Commission were therefore unlawfully collected, and United is obligated to make restitution of the excess payments. Cf.
Baltimore & Ohio R. Co.
v.
United States,
Affirmed.
Notes
“Sec. 4. . . . (c) Under such rules and regulations as the Commission may prescribe, every natural-gas company shall file with the Commission, within such time (not less than sixty days from the date this Act takes effect [June 21, 1938]) and in such form as the Commission may designate, and shall keep open in convenient form and place for public inspection, schedules showing all rates and charges for any transportation or sale subject to the jurisdiction of the Commission, and the classifications, practices, and regulations affecting such rates and charges, together with all contracts which in any manner affect or relate to such rates, charges, classifications, and services.
“(d) Unless the Commission otherwise orders, no change shall be made by any nаtural-gas company in any such rate, charge, classification, or service, or in any rule, regulation, or contract relating thereto, except after thirty days' notice to the Commission and to the public. Such notice shall be given by filing with the Commission and keeping open for public inspection new schedules stating plainly the change or changes to be made in the schedule or schedules then in force and the time when the change or changes will go into effect. The Commission, for good cause shown, may allow changes to takе effect without requiring the thirty days’ notice herein provided for by an order specifying the changes so to be made and the time when they shall take effect and the manner in which they shall be filed and published.
“(e) Whenever any such new schedule is filed the Commission shall have authority, either upon complaint of any State, municipality, or State commission, or upon its own initiative without complaint, at once, and if it so orders, without answer or formal pleading by the natural-gas company, but upon reasonable notice, to enter upon a heаring concerning the lawfulness of such rate, charge, classification, or service; and, pending such hearing and the decision thereon, the Commission, upon filing with such schedules and delivering to the natural-gas company affected thereby a statement in writing of its reasons for such suspension, may suspend the operation of such
“Sec. 5. (a) Whenever the Commission, after a hearing had upon its own motion or upon complaint of any State, municipality, State commission, or gas distributing company, shall find that any rate, charge, or classification demanded, observed, charged, or collected by any natural-gas company in connection with any transportation or sale of natural gas, subject to the jurisdiction of the Commission, or that any rule, regulation, practice, or contract affecting such rate, charge, or classification is unjust, unreasonable, unduly discriminatory, or preferential, the Commission shall determine the just and reason
United agreed to pay Mobile 2 cents per MCF for transporting the gas to Ideal. Since under the assigned contract United received only 12 cents per MCF from Ideal, its net return after the assignment was only 10 cents per MCF, less than the 10.7 cents it had received under its earlier contract with Mobile.
See note 1, pp. 334-336, supra.
See § 14 (a) of the Act, providing in part: “The Commission may permit any person to file with it a statement in writing ... as to any or all facts and circumstances concerning a matter which may be the subject of investigation.” 52 Stat. 828, 15 U. S. C. § 717m.
Mobile Gas Service Cory.
v.
F. P. C.,
Sierra Pacific Power Co.
v.
F. P. C.,
96 U. S. App. D. C. 140,
See also
Colorado Interstate Gas Co.
v.
F. P. C.,
Tyler Gas Service Co.
v.
United Gas Pipe Line Co.,
E. g., City of Lamar
v.
Town of Wiley,
E. g., Rutland R. L. & P. Co.
v.
Burditt Bros.,
