MILLER, Judge.
These appeals are from separate orders of the district court granting summary judgment in favor of defendant-appellee Western Slope Gas Company (“Western Slope”). The judgment against Superior Oil Company (“Superior”) was entered pursuant to Western Slope’s motion for summary judgment. The judgment against Continental Oil Company (“Conoco”) was entered on the court’s joinder of the cases for the purposes of said motion and on its determination that the grant of summary judgment against Superior was decisive of the issues raised in the Conoco case. The orders are vacated, and the cases are remanded.
Background
It appears that the issues before this court in the two cases are, in all material respects, identical. Accordingly, we will direct our attention to only the Superior case,1 with the understanding that the discussion and disposition of that case also apply to the Conoco case.
On January 3, 1964,2 a 20-year contract for the intrastate (in Colorado) sale and purchase of natural gas was entered into by Western Slope, the “Buyer,” and Superior and Conoco, collectively referred to as “Seller.” The contract includes provisions relating to heating value, delivery pressure at the wellhead, measurement (unit of measurement is 1,000 cubic feet (“MCF”) of gas at base temperature of 60 degrees Fahrenheit and pressure of 15.025 pounds per square inch absolute), specific gravity, deviation from Boyle’s Law, and degree of purity-
The contract states that, subject to adjustment for differences in heating value, the base price for deliveries prior to August 17, 1967, is 13<p per MCF, 14c per MCF for the next five years, with a l<t per MCF increase for each five years thereafter. However, Article 8.4 (“FAVORED NATIONS CLAUSE”), provides, in pertinent part, as follows:
If, at any time during the term of this Agreement, Buyer pays to a producer of natural gas in Mesa, Garfield and Rio Blanco County, Colorado, for the purpose of reselling such gas in its Colorado market area, a price per MCF higher than that being paid to Seller hereunder, due consideration being given to the quality of the gas, bases of measurement, delivery pressure, and other conditions of sale, Buyer shall, commencing upon the date of the first delivery of such natural gas at such higher price, and continuing so long as such higher price is paid for such gas, increase the price being paid to Seller hereunder to equal such higher prices.
. [Emphasis supplied.]
Thus, as the district court found, “A favored nations clause ensures that the seller receives the highest price paid by the buyer . to any other seller in a specified area for a substantially similar product.” (Emphasis supplied.)
Article 7.1 (“INTRASTATE UTILIZATION”), provides in pertinent part as follows:
[1283]*1283Buyer represents that it is engaged solely in intrastate transportation of natural gas within the State of Colorado and represents that gas purchased hereunder shall be sold and used only in connection therewith. In the event Buyer should, at any time, propose to sell or use gas purchased hereunder in such manner that in Buyer’s good faith judgment will subject Seller to the jurisdiction of the Federal Power Commission or any successor body thereto with respect to the sale made hereby, Buyer shall notify Seller at least ninety (90) days before such resale or other disposition is commenced and Seller shall have the right hereunder, upon thirty (30) days’ notice to Buyer to terminate this Agreement. .
Subsequent to the district court’s orders dated July 29, 1977, the functions vested in the Federal Power Commission (“FPC”) were transferred to the Secretary of Energy under 42 U.S.C. § 7151(b).
Under date of October 24, 1972, and regarding the contract of January 3, 1964, Western Slope wrote to Superior as follows:
With reference to the gas we are currently purchasing from you under the above gas purchase agreement, Article 8.4 provides that in the event Western pays a higher price to others under certain conditions, you shall be entitled to an equivalent price. We have analyzed the applicable conditions and have concluded that Western has commenced paying a higher price to which you are entitled under the above Article.
The price that Western is paying is the ceiling rate as set forth in FPC Order 435. . . . The price is subject to the terms and conditions of the FPC Order which provides for appropriate discounts from the ceiling rate for water content, inert gas, delivery pressure and BTU content. The applicable ceiling rate is 23.75c per MCF at 15.025 psia. .
As a result of the above, the average price to be paid by Western under our gas purchase agreement is 23.75c per MCF. The effective date for payment of the above price is November 14, 1971, subject to the conditions hereinafter stated. Western will continue to pay this price for so long as it pays an equivalent price to another as provided in Article 8.4. The price is subject to change in the event that (a) the quality or conditions of delivery of the gas we are receiving from you changes; or (b) FPC Order No. 435 is declared to be invalid or is modified by subsequent FPC Orders. . . . [Emphasis supplied.]
This appears to have been the first time that the favored nations clause was triggered. Particularly to be noted is that FPC Order 435 applied to gas sold under contracts dated on or after June 17, 1970. Even though the contract with Superior was dated January 3, 1964, Western Slope considered that its payment of 23.75C per MCF to another producer triggered Article 8.4.
A similar letter, dated May 30, 1974, from Western Slope to Superior advised that on May 15, 1974, Western Slope commenced paying a higher price to which Superior was entitled, namely: 35c per MCF. The letter stated:
Western will continue to pay this price for so long as it pays an equivalent price to another as provided in Article 8.4. The price is subject to change in the event that the quality or conditions of delivery of the gas we are receiving from you changes.[3] [Emphasis supplied.]
We note that the higher price that Western Slope had begun paying on May 15, 1974, was under a contract with another producer which provided for a price of 35c per MCF for gas delivered from wells drilled on or [1284]*1284after January 1, 1973. On June 5, 1974, Western Slope received gas under another contract also providing a base price of 35$ per MCF (without regard to vintage).
About this time, Western Slope began including in new contracts with intrastate producers an “F.P.C. price protection clause,” which provides an alternative (“which results in the greater price to Seller”) to the base price. Such a clause typically reads:4
The price established from time to time by the Federal Power Commission (or any successor agency) as the area ceiling price or rate so authorized, for the specific area within which subject gas well or wells are located, subject to the same general terms and conditions as applicable to such base price which shall include any vintage dates specified by the Federal Power Commission.
“Vintage dates” relate to dates when wells are drilled, with gas from older wells being priced lower than gas from recently drilled wells. Thus, an “F.P.C. price protection clause” is designed to incorporate FPC price regulations into intrastate contracts.
By letter to Western Slope dated February 21, 1975, Superior complained that Western Slope had advised that it was entitled to a price of only 45$ per MCF (note 3, supra), whereas Western Slope was paying a price for gas within the favored nations area which was equal to that prescribed by the Federal Power Commission in Opinion No. 699, June 21, 1974 (50$ per MCF). Western Slope replied on February 27,1975, that the contract under’ which it was paying the higher price called for the same price as that for interstate gas from wells connected after January 1, 1973; further, that:
[W]e have been advised that the vintage date provisions as established by the F.P.C. and which have been incorporated into our more recent gas supply contracts are legitimate conditions of sale and apply equally to those contracts and to contracts containing Favored Nations clauses. [Emphasis supplied.]
Superior wrote back on March 11, 1975, stating:
We call your attention to that certain letter directed to Superior from your company dated October 24, 1972 [supra] advising us that we were entitled to receive a price equivalent to'that under Federal Power Commission Order No. 435 by virtue of the Favored Nations provision in our contract. As you know, Order 435 applied to gas sold under contracts dated on or after June 12, 1970. Since our contract is dated January 3, 1964 if vintaging hid in fact been applicable in order to distinguish between contract dates or well' commencement dates it would have followed that the price increase prescribed under Order 435 would have had no application to gas produced under our contract. However, this was not the case as was evidenced by your letter advising of that particular rate increase. Therefore, it would seem inconsistent with the position that Western Slope is taking which attempts to restrict the Opinion 699 price only to gas produced from wells commenced after January 1, 1973.
[1285]*1285Western Slope’s response on March 25,1975, rejecting Superior’s position, included the following:
In reference to F.P.C. Opinion 435, Docket Nos. R-389 and R-389A and in relation to our letter dated October 24, 1972, Western made a business decision at that time to increase our favored nations contracts to the price specified by Opinion 435 regardless of the contract date mentioned in said Opinion. At that time, contract dates were not considered to be an important factor in future F.P.C. Dockets. As we were obligated to pay this price to other contracts which contained F.P.C. price protection clauses, this price was then paid to all favored nations contracts. At that time, it was indicated that the rulemaking proceedings in Docket Nos. R-389 and R-389A would remain in effect and would be subject to additional requirements, restrictions and authorizations until such time as the Commission declared other just and reasonable rates in the Rocky Mountain Area.
As Opinion 435 set rates for the Rocky Mountain Area for sales under contracts dated after June 17, 1970 and knowing that further proceedings might become effective regarding rates and dates, we decided to go ahead and pay all our favored nations contracts based upon this information and Opinion until such time as further proceedings would set such rates in the Rocky Mountain Area. Further proceedings were consequently held and as a result, Opinion 658 was issued on April 11, 1973, revising the initial rates for the Rocky Mountain Area. This Opinion set out new rates for the Rocky Mountain Area for gas sold under contracts dated prior to October 1, 1968 and produced from wells commenced on or before December 31, 1972. At that time we made a decision that Opinion 658 established vintaging as a requirement for the prices provided for and at that time Western reviewed all contracts containing F.P.C. price protection clauses to determine the effect of Opinion 658. Western did not have any contracts that were affected by that Opinion, and did not change any favored nations contracts.
Subsequent to Opinion 658, Western has been consistent with all of its Sellers in regard to pricing and vintaging as specified by F.P.C.[5]
Superior filed its complaint against Western Slope on September 3, 1976, alleging failure to pay the full contract price for gas purchased by Western Slope from Superior according to Article 8.4 (FAVORED NATIONS CLAUSE) of the Gas Purchase Agreement for the period June 21, 1974, to September 24, 1975. Judgment in the amount of $39,444.80, with costs and interest, was demanded. Western Slope answered with a general denial, an assertion that Superior’s interpretation of the contract would render it “void and unlawful as against public policy,” and the further assertion that Superior had “waived the provisions of the agreement of which it now complains.” On April 21, 1977, by leave of the court, Superior’s complaint was amended to declare the period of the alleged breach to be “from June 21, 1974, to the present time,” and to change the amount of the judgment demanded to $431,315.16 plus any additional sums that may become due during the pendency of the action, together with costs and interest. On April 29, 1977, Western Slope moved for summary judgment. On May 6, 1977, the Public Utilities Commission (“PUC”) of the State of Colorado moved to intervene as a party defendant or to file an amicus curiae brief. The motion to intervene was denied, but permission to file an amicus curiae brief was granted. As noted by the district court, and contrary to Western Slope’s assertion in its answer to Superior’s complaint, PUC’s amicus brief urged that favored nations clauses not be [1286]*1286declared contrary to public policy.6 On May 12, 1977, Western Slope filed a general denial to the amended complaint and incorporated by reference its original answer. On May 17, 1977, counsel stipulated that the separate actions by Superior and Conoco against Western Slope may be consolidated for all purposes and that Western Slope’s motion for summary judgment against Superior was fully applicable to the action by Conoco against Western. Slope. The district court, by order of May 23, 1977, declined to consolidate the cases for all purposes “at this time,” but directed that the motion for summary judgment apply to both cases.
■ On June 17, 1977, an affidavit by Francis X. Barry, currently employed by Superior, was submitted in opposition to Western Slope’s motion for summary judgment. It recites that he was Supervisor of Natural Gas and Product Sales in 1964 and that his duties included the negotiation of gas sales contracts; that, based on his knowledge and experience in the industry, in 1964 the concept of vintaging, as developed by the FPC, “played no part in intrastate gas sales contracts”; that the phrase “other conditions of sale” used by Superior in intrastate gas sales contracts “refers solely to the physical characteristics of the gas sale [sic], such as quality, temperature, pressure and delivery point”; and that the phrase “other conditions of sale” used in Article 8.4 of the gas purchase agreement between Superior and Western Slope “refers solely to the comparability of the sale [sic] based on physical characteristics."
On July 8,1977, an affidavit by Robert F. Jonas, Vice President and General Manager of a wholly-owned subsidiary of Public Service Company of Colorado, was submitted in support of Western Slope’s motion for summary judgment. It recites that he was employed by Western Slope in 1963 and 1964 as the Superintendent of Gas Supply and supervised preparation of numerous gas purchase contracts, including the January 3, 1964, Gas Purchase Agreement between Western Slope and Superior and Conoco; that the intent of requiring consideration of quality of gas, bases of measurement, delivery pressure, and other conditions of sale in connection with the administration of Article 8.4 “was to ensure physical and economic or price comparability with other sales of gas”; that “A principal reason for looking at physical comparability is that variations in quality, heating value, pressure, etc., are considered to affect the economic value of the gas”; that the purpose of the phrase “other conditions of sale” in Article 8.4 “was to cover other factors that were not otherwise enumerated that might affect future comparability of the economic value of the natural gas”; and that, based on his thirty years’ experience, he was “unaware of any physical characteristics related to gas sales other than quality, bases of measurement, and delivery pressure that are not already defined in the gas purchase agreement.” 7
District Court Order Granting Summary . Judgment for Western Slope
The district court, concluding that the favored nations clause does not trigger the payment of higher rates for all gas without regard to its vintage, granted Western [1287]*1287Slope’s motion for summary judgment on July 29, 1977.
The court noted that the purpose of including a favored nations clause in a gas purchase agreement “was to protect the seller over the period of the long-term contract by ensuring price comparability with other gas sold in the designated area or field.”8 It found that, in 1964, “the concept of vintaging was not a ‘condition of sale’ contemplated by the parties for purposes of establishing comparability of gas under the favored nations clause” and the “significance of vintaging was both unforeseen and unforeseeable”; that the “significance of vintaging for interstate gas contracts could not have been recognized until 1971, when the FPC initially developed this concept.”9 (Emphasis supplied.) Nevertheless, it said:
We hold that the phrase “other conditions of sale” in Article 8.4 of the contract includes vintage and other factors that influence the value of gas sold to Defendant by other buyers [sic, “sellers”] in the area specified therein. [Footnote omitted; emphasis supplied.]
In support of this holding, the court reasoned:
If a long-term contract is to be maintained, its provisions must be interpreted, if possible, in a manner that permits the continuing viability of such contracts in a world of changing externalities. . . .
Plaintiff’s interpretation of Article 8.4 ignores the vintage of gas for purposes of determining its comparability with gas produced by other companies in the area. Only four of Plaintiff’s wells were commenced on or after January 1, 1973J[10] However, Plaintiff insists on being paid new vintage gas prices for all gas delivered to Defendant. Plaintiff would thereby be treated more favorably than other producers which sell gas to Defendant, a result that is not called for by any form of price equalization clause. If particular relevant factors of comparability were not considered, such clauses would quickly be recognized as unjust, would not be included in contracts, and long-term gas contracts would no longer be made. The public might suffer from the absence of long-term commitments of adequate gas. . . . Vintage has become a significant factor in determining the value of gas, and must be considered in comparing gas for purposes of triggering a price equalization or escalation clause.
Defendant’s construction of Article 8.4, which permits consideration of vintage in determining the comparability of gas, is the only reasonable interpretation of the contract. . . .
As we have seen, the FPC developed the concept of vintaging in order to-account for increased cost of production from newly-drilled wells.[11] The favored [1288]*1288nations clause was inserted in the contract in order to ensure that Plaintiff would be paid a fair value for its gas over the 20-year period of the contract. The value of gas is directly related to the cost of its production. Therefore, vintage is an essential factor in determining comparability of gas for purposes of the favored nations clause.
Referring to Pure Oil Co. v. F.P.C., 299 F.2d 370 (7th Cir. 1962), as the “leading case on the issue of what factors should be considered by the Court in interpreting a favored nations clause,” the district court quoted from the opinion in that case, id. at 373, thus:
And, inasmuch as it is the actual comparative values which must determine the true relationship of prices as being higher, equal or lower, we perceive no error in the legal conclusion, inherent in the Commission’s determination, that the comparability clauses require consideration and comparison of all factors, whether or not the express subject of contract provision, which are pertinent to arriving at the value of the gas as delivered. Such factors, while not embracing purely subjective elements which may represent value to the particular purchaser only, do include those attributes and characteristics which serve to measure the value for pipe line distribution purposes of the gas contracted to be delivered.
Finally, the court said that FPC’s rejection of contracts containing favored nations clauses does not extend to intrastate contracts and that it expressed “no view as to whether favored nations clauses are void as a matter of public policy.” However, it quoted from Permian Basin Area Bate Cases, 390 U.S. 747, 782-83, 88 S.Ct. 1344, 1368, 20 L.Ed.2d 312, 344-345 (1968) as follows:
Indefinite escalation clauses “cause price increases ... to occur without reference to the circumstances or economics of the particular operation, but solely because of what happens under another contract.” 34 F.F.C., at 373. There is substantial evidence that in design and function they are “incompatible with the public interest. . . .” Order No. 232, 25 F.P.C. 379, 380. Indeed, this Court has already entirely sustained the Commission’s 1962 order. FPC v. Texaco, 377 U.S. 33, 84 S.Ct. 1105, 12 L.Ed.2d 112 [1964]. [Footnote omitted.]
Opinion
The dispositive issue raised by this appeal is whether the phrase “other conditions of sale” in Article 8.4 of the contract between the parties includes vintage, which was established by regulations of the FPC for interstate sales of natural gas.12 If such vintage is so included, payment by Western Slope of higher prices to sellers pursuant to an “F.P.C. price protection clause” did not trigger the favored nations clause in the parties’ contract; if such vintage is not so included, such payment did trigger the favored nations clause, thereby entitling Superior to the higher prices it has claimed.
Because the parties are in dispute over the meaning of the phrase “other conditions of sale,” it is necessary to determine, if possible, what the intent of the parties was at the time they entered into the contract. 4 Williston on Contracts, § 600 at 284-85 (3d ed. 1961). As this court stated in Ten-neco Oil Co. v. Gaffney, 369 F.2d 306, 308 (10th Cir. 1966):
It is the court’s duty to construe the instrument “so as to effectuate the manifest intention of the parties — to give life and vitality to the language the parties have used to express their agreement.” Ryder Truck Rental, Inc. v. Central Packing Co., 10th Cir., 341 F.2d 321, 323-24, cert. denied 382 U.S. 827, 86 S.Ct. 60, 15 L.Ed.2d 71. “It is well established * * that in interpreting a written contract, the court should, as far as possible, place [1289]*1289itself in the position of the parties at the time of its execution, and then, from a consideration of the instrument itself, its purposes, and the circumstances surrounding its execution, ascertáin the intention of the parties. * * * ” United States v. Essley, 10th Cir., 284 F.2d 518, 520.
If the intent of the parties cannot be determined from the contract itself, then other evidence must be considered.
With respect to the contract itself, if there is any point on which there is “manifest intention” of the parties, it is, that they not come under FPC control — at least insofar as gas purchased under the contract is concerned. This is clearly shown by Article 7.1 (“INTRASTATE UTILIZATION”). Western Slope’s position (that FPC’s vin-taging regulations, although “unforeseen and unforeseeable” and “not a ‘condition of sale’ contemplated by the parties” in 1964, come within the scope of the phrase “other conditions of sale” and, therefore, control the price of gas purchased by Western Slope from Superior) is clearly contrary to such manifest intention of the parties. It is true that such control by FPC would not be direct, as in the case of an “F.P.C. price protection clause,” where the seller has voluntarily submitted to the bitter of FPC vintaging regulations in exchange for the sweet of an increased price. But direct or indirect, the substance of such an interpretation of “other conditions of sale” would simply be to rewrite the favored nations clause (quoted earlier) by adding at the end thereof the following:
Provided, that if said higher price is paid pursuant to an “F.P.C. .price protection clause” in the contract between Buyer [Western Slope] and said producer, and said higher price is contingent upon said producer’s compliance with vintaging regulations of the FPC, said higher price shall be paid Seller [Superior] only if it is in compliance with said vintaging regulations of the FPC.
As this court said in Quad Construction, Inc. v. Wm. A. Smith Contracting Co., 534 F.2d 1391, 1394 (1976): “The courts interpret contracts as made by the parties and do not make new ones for them. Yamin v. Levine, 120 Colo. 35, 206 P.2d 596, 597 [1949].”
. Our conclusion with respect to the manifest intention of the parties is reenforced by evidence of Western Slope’s own interpretation (prior to the dispute) of the phrase “other conditions of sale” as not including vintaging. We* have earlier pointed to Western Slope’s letter, dated May 30, 1974, advising Superior that on May 15 it had commenced paying to another producer a higher price (350 per MCF) to which Superi- or was entitled; this notwithstanding that the higher price to the other producer was for gas from wells drilled on or after January 1, 1973.13 Although Superior asserts that such action estops Western Slope from maintaining that Superior is not entitled to the higher prices paid other producers within the favored nations area, without reaching that issue, we regard such action as evidentiary of the understanding and intent of the parties that the phrase “other conditions of sale” not encompass vintage established by FPC regulations.
Western Slope argues that “other conditions of sale” in the favored nations clause should be interpreted as though reading “other conditions of the other sale” (/. e. the [1290]*1290sale from another producer to Western Slope which would trigger the clause). Assuming arguendo that such an interpretation were correct, it would mean that the “other conditions of sale” (to Western Slope from another producer) must be compared to the “other conditions of sale” to Western Slope from Superior for the purpose of determining price comparability: Significantly, in its-letters to Superior dated October 24, 1972, and May 30, 1974 (and in its letter to Conoco dated January 15, 1975), Western Slope, in giving assurance that it would pay a higher price as long as it pays an “equivalent price” to another, appears to equate “conditions of delivery of the gas” with' “conditions of sale.” Clearly, “conditions of delivery of the gas” would not include date of drilling of the wells. Rather, as noted earlier (note 7, supra), such conditions would include (a) delivery pressure (specifically listed in the favored nations clause but not in the referenced letters from Western Slope), (b) delivery location, (c) installation, maintenance, and operation of equipment, (d) size, type, location, and method of setting of meters, (e) ownership, control, and possession of the gas, and (f) delivery taxes.
Superior and Amicus argue that, under the rule of ejusdem generis,14 the phrase “other conditions of sale” relates to physical characteristics of the gas not specifically listed, such as compression, deliverability, and treatment of the gas. Western Slope responds that “the enumeration which precedes the language [“other conditions of sale”] includes all the relevant physical characteristics of gas,” so that, to give effect to the language, “other conditions of sale” cannot be restricted to physical characteristics. Broadly construed, the words “quality of the gas, bases of measurement, [and] delivery pressure” that precede the phrase “other conditions of sale” would appear to include all physical characteristics, including compression, deliverability, and treatment of the gas, so that “other conditions of sale” would have to encompass something more if the phrase is to be meaningful. But this is not reconcilable with the district court’s finding that a favored nations clause “ensures that the seller receives the highest price paid by the buyer . . . to any other seller in a specified area for a substantially similar product.” (Emphasis supplied.) Moreover, it does not compel the conclusion that contrary to the manifest intention of the parties, the phrase must encompass vintaging established by regulations of the FPC and not even contemplated by the parties. Rather, it would seem more likely that the parties intended the phrase to encompass “conditions of delivery of the gas.” Narrowly construed, the words that precede the phrase “other conditions of sale” would not necessarily include such physical characteristics as treatment of the gas, compression, and peaking capability, so that the phrase “other conditions of sale” could reasonably be interpreted to relate only to physical characteristics of the gas.
Finally, Western Slope (as did the district court) relies heavily on Pure Oil v. F.P.C., 299 F.2d 370 (7th Cir. 1962), for support of its position that “all factors, such as vintage, relevant to determine price comparability, whether mentioned in the contract or not, should be considered.” We observe, however, that the favored nations clauses in that case were not the same as the one before us, two of them providing:
* * * In determining whether the price payable under such other contract or agreement is “higher” than the price payable for gas under this agreement, due consideration shall be given to the provisions of this agreement as compared with such other contract or agreement as to quantity and quality of gas, delivery pressures, gathering and compressing arrangements, provisions regarding measurement of gas including deviation from Boyle’s Law, taxes payable on or with respect to such gas, and all other pertinent factors.
The case involved interstate gas. It was not concerned with vintaging (a concept unforeseen at the time) or with an intra[1291]*1291state utilization provision. The issue »was whether the phrase “all other pertinent factors” included exceptional peaking capacity to which the higher price paid under another contract was attributable. The court held that the factor of peaking capacity was included, so that a price increase under the favored nations clause was not triggered. It said, inter alia, 299 F.2d at 373:
Pure contends the determination of “higher price” is limited to a comparison of these specified elements and such other pertinent factors as appear from the face of the contracts, and that the “all other pertinent factors” provision of the clauses does not extend to a factor such as peaking quality or capacity, a quality not an express subject of some provision or term of the contracts.
We agree with Pure that resolution of this issue of contract construction does not involve a matter which falls within the purview of Commission expertise but we are not persuaded by any of the arguments advanced by Pure that the record evinces an intention of the parties to limit the ordinary import and breadth of scope of the language “all other pertinent factors” in the manner contended for by Pure. . . . Such factors, while not embracing purely subjective elements which may represent value to the particular purchaser only, do include those attributes and characteristics which serve to measure the value for pipe line distribution purposes of the gas contracted to be delivered. [Emphasis supplied.]
We agree with the decision in the Pure Oil case. Peaking capacity would reasonably be considered among the “attributes” or “characteristics” to be taken into account in measuring the value of gas for pipeline distribution. See Shell Oil Co. v. F.P.C., 334 F.2d 1002 (3d Cir. 1964). At the same time, we are not persuaded that well-drilling dates (vintage) constitute such “attributes” or “characteristics,” since there is no difference between “old” and “new” gas for distribution or consumption purposes.
Although we would agree with the district court that vintage has become a significant factor in the pricing of interstate gas, we do not indulge the district court’s speculation that failure to consider vintage in comparing gas for purposes of triggering a favored nations clause in intrastate gas purchase agreements would mean an end to long-term gas contracts and that this might be harmful to the public.15 Moreover, as earlier related (note 6, supra), the Colorado PUC urged the district court to not declare favored nations clauses void as contrary to public policy, and the court said it expressed no view on that matter.16
In view of the foregoing, we hold that, on the facts of this case, the phrase “other conditions of sale” in Article 8.4 of the contract between the parties does not include vintaging established by regulations of the FPC for interstate sales of natural gas.
The orders of the district court are vacated, and the cases are remanded for further proceedings consistent with this opinion.