JERRE S. WILLIAMS, Circuit Judge:
Gulf States Utilities sued the Southern Companies over two contracts for the purchase and sale of electricity. The district court took jurisdiction over the case pursuant to 28 U.S.C. §§ 1332 (diversity of citizenship) and 2201 (declaratory judgment). Southern appeals, asserting lack of jurisdiction in the district court.1 Southern’s contention is that the Federal Power Act preempts Gulf States’ claims and that only the Federal Energy Regulatory Commis[1468] sion may resolve this case. We affirm the district court’s exercise of jurisdiction.
I. Facts
Gulf States Utilities (“GSU”) and the Southern Companies (“Southern”) are public utilities engaged in the interstate purchase and sale of electricity. As such, they are regulated by the Federal Power Act (“FPA”), 16 U.S.C. § 824 et seq. Under the FPA, public utilities are limited to charging just and reasonable rates for electricity sold in interstate commerce. 16 U.S.C. § 824d(a). The Federal Energy Regulatory Commission (“FERC”) has exclusive jurisdiction over interstate wholesale power rates: utilities must file their rates with the FERC, and the FERC can approve or alter such rates. 16 U.S.C. § 824e(a); Nantahala Power & Light Co. v. Thornburg, 476 U.S. 953, 106 S.Ct. 2349, 2352, 90 L.Ed.2d 943 (1986).
Southern makes electricity mainly from coal, while GSU uses mainly oil and gas to produce its electricity. GSU sells most of its electricity to customers in Louisiana and Texas at rates regulated by, respectively, the Louisiana Public Service Commission (“LPSC”) and the Public Utilities Commission of Texas (“PUCT”).
In 1982, GSU contracted to buy electricity from Southern through 1992. Apparently, GSU forecasted that through 1992 (1) demand for its electricity would increase and (2) electricity produced by coal would be cheaper than electricity produced by oil and gas. GSU now alleges, however, that both (1) oil and gas prices and (2) the demand for electricity in Louisiana and Texas fell after 1982. In addition, the PUCT allegedly reduced the rate that GSU may charge its retail customers, refusing to allow GSU to recover the full cost of the electricity it buys from Southern. Because of these factors, GSU wants to avoid its contractual obligations to buy electricity from Southern.
a. The GSU — Southern Contracts
On February 25, 1982, GSU and Southern signed two contracts. One contract, the Unit Power Sales (“UPS”) contract, provided that GSU would buy 500 megawatts (“MW”) per year of electricity through 1992. It also provided:
§ 2.2.1: In the event either party desires to increase or decrease capacity sales or purchases ..., the parties agree to negotiate in good faith and with diligence to proceed to evaluate alternatives which may reasonably provide for such desired change in capacity; provided, that no such change shall be made except upon mutual written agreement of the parties hereto.
The other contract, the “Interchange” contract, governed the connections between GSU’s and Southern’s facilities. The Interchange contract provided, in § 9.4, that “[i]n the event this CONTRACT is changed or modified by any regulatory agency or authority, either party, if adversely affected, shall have the right to negotiate for the necessary relief to alleviate said adverse effects....”
On May 12, 1982, GSU and Southern amended the UPS contract to increase the amount of electricity purchased after May 1985 to 1,000 MW/year. As required by the FPA, GSU and Southern filed the Interchange and amended UPS agreements with the FERC. See 16 U.S.C. § 824d(c).
On December 6,1983, GSU and Southern again amended the UPS agreement, this time to reduce the amount of electricity to be purchased by GSU between 1985 and 1992.2 Also on December 6,1983, GSU and Southern amended the Interchange contract by adding “Schedule E.” Under Schedule E, GSU agreed to supplement its basic UPS purchases between 1985 and 1992 by buying available “Long Term Power.” The term “Long Term Power” means “capacity and energy existing on [Southern’s] system ... not needed at that time ... to meet its own system requirements (including power used for pumping at pumped storage hydroelectric projects) and [Southern’s] other power sale commitments ... taking precedent before delivery under this Schedule [E].” In all, GSU agreed to buy enough available Long Term Power to [1469] maintain its total purchases from Southern at 1,000 MW/year between 1985 and 1992.3 Long Term Power is cheaper than UPS power, and the FERC approved Schedule E and the 1983 amendments to the UPS contract.
b. The Trouble Since 1983
As set out above, GSU claims that demand for its electricity has decreased and that lower oil and gas prices have made Southern’s coal-generated electricity relatively more expensive than electricity made from oil and gas. In addition, the PUCT reduced the rates that GSU could charge its customers and did not let GSU pass through to customers the cost of electricity bought from Southern. For these and other reasons, GSU requested renegotiation of its obligations under the UPS and Interchange contracts. GSU and Southern negotiated unsuccessfully until July 2, 1986, when GSU sued Southern in federal district court.
GSU’s complaint explained that both GSU and Southern originally assumed that their contracts would be mutually beneficial through 1992 but that unforeseeable market conditions and PUCT decisions have spoiled the deal for GSU. GSU apparently searched the lawbooks to unearth every conceivable cause of action. First, it claims that Southern refused to renegotiate its contracts in good faith. This failure allegedly constitutes a breach of contract and also a breach of an independent duty to act in good faith. GSU also claims that, in making the contracts, Southern never intended to renegotiate in good faith but fraudulently promised to do so. GSU also pleads that Southern “unconscionably” exploited GSU and breached an “implied warranty” to renegotiate, in violation of the Texas Deceptive Trade Practices Act (“DTPA”). GSU also alleges that unfor-seeable actions of the PUCT and changes in market conditions (1) legally excuse GSU’s performance, (2) render GSU’s performance commercially impracticable, (3) frustrate the purpose of the GSU-Southern contracts to serve the public, and (4) manifest mutual and unilateral mistakes in the making of the contracts. GSU also claims that its contracts with Southern are unconscionable. Finally, GSU claims that Southern has exaggerated the amount of available “Long Term Power” that GSU must buy under Schedule E. Specifically, GSU asserts that Southern is engaging in “cannot lose” dealing by buying inexpensive, oil-and-gas-generated electricity from GSU and selling it right back to GSU at a profit under Schedule E. GSU seeks money damages and an order voiding the contracts.
The main issue in this appeal is whether the district court — or only the FERC — has jurisdiction over GSU’s multi-faceted complaint. A subordinate issue is raised because shortly after filing suit GSU stopped making payments to Southern and started depositing the money due under its contracts into the registry of the district court. Over Southern’s objection, the district court accepted these funds under Fed.R. Civ.P. 67. Southern claims on appeal that the deposits are improper. Finally, a third issue is raised by a motion of the LPSC to intervene in GSU’s suit under Fed.R.Civ.P. 24. The district court denied the LPSC’s request, and the LPSC appeals.
In this opinion, we first hold that the district court does have jurisdiction over at least some aspects of this suit because the FERC’s jurisdiction over GSU’s complaint is not exclusive (Part II) or primary (Part III). Then we hold that the district court did not abuse its discretion by allowing GSU to deposit with the court payments allegedly due under the contracts (Part IV), but that the district court erred in barring intervention in this litigation by the LPSC (Part V).
II. Exclusive Jurisdiction
a. The Filed Rate Doctrine
The FPA gives the FERC exclusive jurisdiction over interstate wholesale electricity rates. See 16 U.S.C. §§ 824-824e. The FPA permits utilities to charge only just [1470] and reasonable rates and to file their rates and sales contracts with the FERC. 16 U.S.C. § 824d(a-c). The FERC may review the filed rates and, if it finds a rate to be unjust or unreasonable, it may fix a just and reasonable rate. 16 U.S.C. § 824e(a).
Through the FPA, Congress preempted states, state courts, and even federal courts from acting in areas reserved exclusively for the FERC.4 For example, under the FPA, a buyer or seller of electricity may not sue in court to change the filed rate for any reason. See e.g., Montana-Dakota Utilities Co. v. Northwestern Public Service Co., 341 U.S. 246, 250, 71 S.Ct. 692, 694, 95 L.Ed. 912 (1951) (under the “filed rate doctrine,” a court may neither adjudicate whether a rate is reasonable nor replace a filed rate with a more reasonable one).
In addition, the FPA forbids a state or state agency to impose a rate different from the filed rate or to interfere with the purchasing or transporting of electricity in a way that affects rates. In Transcontinental Gas Pipeline Co. v. State Oil & Gas Board of Mississippi, 474 U.S. 409, 106 S.Ct. 709, 88 L.Ed.2d 732 (1986), a pipeline company contracted to buy gas from some but not all producers in a common gas pool.5 Drawing gas from a few wells in the pool threatened to deplete the entire pool. The state’s gas board sought to protect the correlative rights of all producers in the pool and thus required the pipeline company to buy gas, if at all, from all producers in proportion to their respective ownership interests in the pool. The Supreme Court struck down this regulation because it improperly interfered with the federal scheme regulating interstate gas sales, which allows and encourages pipeline companies to buy gas from the cheapest sources. The Court advised states to prevent physical and economic waste of gas by regulating the production, rather than the purchasing, of gas. Accord Northern Natural Gas Co. v. State Corporation Commission of Kansas, 372 U.S. 84, 83 S.Ct. 646, 9 L.Ed.2d 601 (1963) (striking down a similar state regulation requiring Northern to buy from all producers in a field: the regulation indirectly would affect Northern’s rates and infringe the NGA’s scheme).
Most recently, Nantahala Power & Light Co. v. Thornburg, 476 U.S. 953, 106 S.Ct. 2349, 90 L.Ed.2d 943 (1986), also held preempted a state regulation over a utility’s electricity rates. Nantahala and a company called Tapoco produced electricity for the Tennessee Valley Authority (“TVA”). In return, the TVA provided Nantahala and Tapoco with a fixed quantity of low-cost power, called “entitlement” power. Tapoco resold its share of the entitlement power to ALCOA Corporation, while Nantahala sold its entitlement power, plus power it purchased from other sources at high cost, to wholesale and retail customers in North Carolina. According to the FERC, Tapoco received 77.5 percent of the TVA entitlement power, and Nantahala received 22.5 percent. Under the FERC’s allocation, Nantahala could include only 22.5 percent of the entitlement power among its sources of electricity; that is, it had to compute its costs and set its rates as if it received only 22.5 percent of the entitlement power and purchased the rest.
[1471] The North Carolina Utilities Commission (“NCUC”) regulated the rates of Nantaha-la’s retail sales in North Carolina. In its rate-making procedures, the NCUC determined that Nantahala actually received 24.5 percent of the low-cost entitlement power allocated to Nantahala and Tapoco, rather than 22.5 percent as determined by the FERC. Thus, the NCUC decided that the FERC underestimated the amount of low-cost power available to Nantahala and ordered Nantahala to reduce its rates to reflect the NCUC’s allocation of low-cost electricity. The Supreme Court invalidated the NCUC’s allocation. 106 S.Ct. at 2357. The FERC allocation directly affected Nantahala’s rates and thus bound the NCUC, and no court could adjudicate whether the FERC allocation was reasonable. Id.
The FPA also preempts some private causes of action for breach of contract. In Arkansas Louisiana Gas Co. v. Hall, 453 U.S. 571, 101 S.Ct. 2925, 69 L.Ed.2d 856 (1981) (“Arkla ”), the Supreme Court held that a seller (or buyer) may not sue to change a filed rate even if the buyer (or seller) has contracted to change that rate. Hall sold gas to Arkla from the Sligo Field for a fixed price, but Arkla promised to pay Hall as high a price as it paid to any other producer for Sligo Field gas. Arkla then bought Sligo Field gas from the United States for a higher price than it paid to Hall. Hall discovered Arkla’s breach and sued to recover the difference between the price paid to him and the price Arkla paid to the United States. The Supreme Court rejected Hall’s suit and reiterated the filed rate doctrine announced in Montana-Dakota: regulated sellers must charge only the rate filed with the FERC, and only the FERC — not a court — may change an unreasonable filed rate. 453 U.S. at 577-78, 101 5.Ct. at 2930-31. Moreover, even the FERC may not alter a rate retroactively or order reparations for unreasonable charges in the past. Id. Hall wanted simply a retroactive rate increase, so his claim, based on state contract law, was preempted. Id. at 579, 584, 101 S.Ct. at 2931, 2934. Hall’s only recourse was to ask the FERC to change the filed rate prospectively.
b. Jurisdiction Over GSU’s Complaint
With this discussion of case law on preemption in mind, we now consider the status of GSU’s many state law causes of action. We review these claims and hold that at least some of them are not preempted by the FPA, although the FPA does limit GSU’s available relief.6
Some of GSU’s claims involve Southern’s alleged failure to negotiate under UPS § 2.2.1 or Interchange § 9.4. GSU claims that, if Southern had negotiated in good faith, it would have agreed to file lower rates with the FERC. The FPA clearly preempts this claim. The district court may not compensate GSU on the theory that it would have paid rates different than the filed rates if Southern had not breached. See Arkla. Other relief, however, may be available to GSU for Southern’s alleged failure to negotiate. For instances, UPS § 2.2.1 refers to renegotia-tions regarding “change[s] in capacity.” (emphasis added). GSU might be able to show that good faith negotiations would have reduced the amount purchased (not the rate) under the UPS and Interchange contracts and that GSU was harmed by taking the quantity required in the filed contracts, perhaps by overloading GSU’s capacity. This claim would not be preempted by the FPA. Also, GSU may prove that it suffered damages that are unrelated to any actual or desired rates— such as attorneys’ fees or other expenses incurred during the negotiations. In addition, the district court could order Southern to negotiate in good faith in the future.7
[1472] GSU also claims that the UPS and Interchange contracts should be set aside because Southern committed fraud and deceptive trade practices by falsely promising to negotiate in good faith. Assuming ar-guendo that such relief is available under state law, the FPA would not necessarily forbid the district court to set aside contracts obtained unconscionably or by fraud.8 The FERC does not warrant that filed contracts — such as the UPS and Interchange Agreements — are free from fraud. By setting aside the contracts, the district court would not interfere with the FERC’s rate-making powers.9 We stress, however, that the district court may not set aside the contracts on the theory that Southern’s rates are too high. See Montana-Dakota.
Further, GSU claims that its obligations should be excused because of commercial impracticability, frustration of purpose, changed conditions, mutual mistake, unilateral mistake, unconscionability, and the PUCT’s actions. Southern warns that GSU simply wants to pay lower rates for its electricity and is trying to circumvent the FPA and the FERC with artful pleading. At this early stage in the litigation, GSU has not explained whether commercial impracticability, frustration, or any other defense applies (1) because of high rates (in which case the FPA would preempt) or (2) because of reasons unrelated to rates.
The district court would have jurisdiction if GSU claimed that it cannot take Southern’s electricity regardless of price. If, however, GSU can fulfill its purchase obligations at a lower rate, then GSU seeks only rate relief not available in district court. For instance, GSU claims that state law excuses its performance for “frustration of purpose.” The FPA would preempt a claim that frustration occurs because of high rates; the FPA would not preempt a claim that frustration occurs by buying any electricity from Southern at any price. Perhaps, for instance, accepting additional capacity would overload and damage GSU’s facilities. Dismissal for lack of jurisdiction at this point would be premature, although Southern can request GSU to plead its claims with more specificity. See Fed.R. Civ.P. 12(e).
Finally, GSU complains that Southern has sold more than it should have under Schedule E by overstating the amount of available “Long Term Power.” The FPA does not preempt this claim. Unlike Hall in Arkla, GSU does not seek relief based on a rate different from the filed rate. Rather, GSU complains about the quantity sold at the filed rate under Schedule E. The district court could order Southern to refund amounts wrongfully paid in the past and/or could order Southern to change its calculation of available Long Term Power in the future.
In sum, we hold that the district court properly denied Southern’s motion to dismiss for lack of subject matter jurisdiction.
III. Primary Jurisdiction
The doctrine of “primary jurisdiction” recognizes that an administrative agency, such as the FERC, should be able to participate in decisions affecting a regulated industry, even when the agency does not have exclusive jurisdiction. The doctrine eludes fixed application, but sometimes a court must stay its own proceedings and defer to let an agency “have the first word.” Mississippi Power & Light Co. v. United Gas Pipeline Co., 532 F.2d 412, 417 (5th Cir.1977), cert. denied, 429 U.S. 1094, 97 S.Ct. 1109, 51 L.Ed.2d 541 (1977). The doctrine applies when agency [1473] action would produce needed uniformity in an area or when the agency has “special competence” over the issue to be decided. See United States v. Western Pacific Railroad Co., 352 U.S. 59, 64, 77 S.Ct. 161, 165, 1 L.Ed.2d 126 (1956); accord Carpenters Local Union No. 1846 v. Pratt-Farnsworth, Inc., 690 F.2d 489, 515 n. 11 (5th Cir.1982) (defer to agency if it is “better equipped than court’s by specialization, by insight gained through experience, and by more flexible procedures”), cert. denied, 464 U.S. 335, 104 S.Ct. 335, 78 L.Ed.2d 305 (1983); United States v. McDonnell Douglas Corp., 751 F.2d 220, 224 (8th Cir.1984) (defer if issue requires uniformity of resolution and the agency’s “expert consideration”). Sometimes, the courts should allow an agency to interpret a contract, especially when “words ... are used in a peculiar or technical sense, and where extrinsic evidence is necessary to determine their meaning or proper applications.” Western Pacific Railroad, 352 U.S. at 65-66, 77 S.Ct. at 166 (holding that the Interstate Commerce Commission, not the court, should decide whether napalm gel bombs without fuses or bursters are “incendiary bombs” within the meaning of an ICC tariff).
We have said that a district court in its discretion should invoke primary jurisdiction and defer only if the benefits of obtaining the agency’s aid outweigh the need to resolve the litigation expeditiously. Mississippi Power, 532 F.2d at 419. The district court may consider many factors in striking this balance, including: how agency action will aid the litigation; whether the litigation involves conduct requiring continuing supervision by the agency; whether the issues to be litigated are unique to regulated industries; and whether proceedings already are pending before the agency. Id. at 419-20.
In the case before us, both parties have initiated proceedings before the FERC, but the district court refused to stay the litigation pending the FERC’s decision. Since the district court’s decision and oral argument in this appeal, the FERC’s Administrative Law Judge (“AU”) rendered an initial decision in the GSU-Southern proceedings. Thus, even though the initial decision is likely to be re-considered by FERC, we now have guidance as to the actual scope of the FERC’s inquiry.
In his initial decision, the AU explained that he could grant relief only by finding that the filed contracts were “unjust, unreasonable, unduly discriminatory, or preferential” under 16 U.S.C. § 824e(a). Using this standard, and reviewing almost a month of testimony, he found that Southern’s rates are based on Southern’s costs and thus are not unreasonable. He also found that (1) changed market conditions were foreseeable and, in any event, do not make the contracts unjust or unreasonable; (2) GSU has benefited from the contracts, and the contracts are not unjust or unreasonable simply because they yielded fewer benefits than GSU expected; (3) GSU’s involvement in a nuclear project, not these contracts, caused GSU’s financial woes, and the contracts do not unjustly or unreasonably burden GSU; and (4) the contracts are not unjust or unreasonable even though Southern is larger than GSU. Regarding UPS § 2.2.1, the AU ruled: “Section 2.2.1 does impose an obligation upon the parties to negotiate in good faith and with diligence. Failure to negotiate in good faith and with diligence would constitute a breach of contractual obligation for which a court could fashion a remedy.” Thus the AU specifically accepted the role of a court in fashioning a remedy for breach of contract.
As to other matters, the AU found that “the capacity and energy provided by Southern to GSU under Schedule E constitutes ‘Long Term Power’ as that term is defined in [Schedule E].” He also addressed the effect of the PUCT’s refusal to allow GSU to pass-through the cost of electricity bought from Southern and ruled that the PUCT decision — whether correct or not— does not render the contract unreasonable or unjust. The AU further ruled that the PUCT decision does not excuse GSU’s obligations under its contracts.
In most respects, the AU confined his inquiry to the “just and reasonable” . standard in 16 U.S.C. § 824e(a) and did not address the state law issues at stake in the [1474] litigation. The district court, of course, has no authority to order “just and reasonable” results under 16 U.S.C. § 824e(a). Given the factors discussed in Mississippi Power, the district court did not err in refusing to apply the doctrine of primary jurisdiction. As we explain above, however, the district court may not grant relief to GSU on the theory that its rates are too high, unconscionable, or the cause of commercial impracticability or any other problems.
Three findings of the AU as set out above raise particular doubts as to the FERC’s primary jurisdiction. These are: (1) the changed conditions about which GSU complains were foreseeable, (2) Southern sold only available Long Term Power under Schedule E, and (3) the PUCT’s decision to disallow GSU’s pass-through did not excuse.GSU's obligations with Southern. The AU stated these findings without elaboration, and no evidence suggests that the FERC proceedings developed a factual record that would aid the district court. Cf. Mississippi Power, 532 F.2d at 420 (“Development of the factual context by those expert in the area is an established basis for primary jurisdiction.”). These findings do not require the district court to stay its litigation. The AU’s findings are not final; the FERC may modify or reverse them. Once the FERC issues its final decision, the district court may adapt its own decision to accommodate the FERC’s as necessary. Moreover, the AU may have exceeded the scope of his primary jurisdiction, because these findings do not seem to require the FERC's special expertise or a uniform rule throughout the nation. Some of them in their present form may not even be within FERC’s jurisdiction. Unless and until the FERC adopts the AU’s findings, we need not decide their effect on the litigation.
Finally, the AU ruled that UPS § 2.2.1, requiring good faith renegotiation, does not apply to the Interchange contract. Under the guidelines set out in Western Pacific Railroad, the district court is not bound by this finding but can interpret the contracts itself as a matter of law. See 352 U.S. at 65-66, 77 S.Ct. at 166.
In sum, the district court did not err in refusing to stay the litigation pending action by the FERC. The district court may address GSU’s claims that Southern failed to renegotiate in good faith, that the UPS and Interchange contracts were induced by fraud, that Southern is selling an improper amount of electricity under Schedule E, and that the quantity of electricity GSU must take under its contracts excuses its performance under various theories of state contract law. As the litigation proceeds and GSU’s theories become clearer, the district court may find that the FERC has exclusive or primary jurisdiction over some of GSU’s claims.
IV. Rule 67 Deposits
As set out above, GSU filed suit on July 2, 1986. On July 11, 1986, it moved to deposit in the district court’s registry the funds allegedly due to Southern. The district court granted GSU’s motion and accepted deposits starting in July 1986 pursuant to Fed.R.Civ.P. 67.
Rule 67, as amended in 1983, provides: In any action in which any part of the relief sought is a judgment for a sum of money or the disposition of a sum of money or the disposition of any other thing capable of delivery, a party, upon notice to every other party, and by leave of court, may deposit with the court all or any part of such sum or thing, whether or not that party claims all or any part of the sum or thing.
The purpose of Rule 67 is “to relieve the depositor of responsibility for a fund in dispute,” such as in an interpleader action. See 12 C. Wright & A. Miller, Federal Practice & Procedure § 2991 (West 1973) (footnotes omitted). The 1983 amendment to Rule 67 makes clear that the depositor may have an interest in the deposited funds. Once funds are deposited, the court should determine ownership and make disbursements. See Baxter v. United Forest Products Co., 406 F.2d 1120 (8th Cir.) (court holds deposits as trustee for the true owner), cert. denied, 394 U.S. 1018, 98 S.Ct. 1635, 23 L.Ed.2d 42 (1969); Manufacturers’ Hanover Overseas Corp. v. South-[1475] wire Co., 589 F.Supp. 214, 221 (S.D.N.Y.1984).
The district court did not abuse its discretion by accepting GSU’s deposits. While GSU’s claim for breach of UPS § 2.2.1 alone might not place the deposited amounts “in dispute,” GSU also claims that its contracts should be set aside as of July 2, 1986 and that it does not owe Southern the deposited money. Southern, of course, claims that GSU owes it the deposited funds. Thus, the funds genuinely are in dispute.10
Baxter v. United Forest Products, supra, is not to the contrary. In Baxter, the plaintiff had bought a business and agreed to pay the purchase price in four installments. If he failed to make any payment, he forfeited the business plus any payments made before the default. When the plaintiff/buyer discovered fraud by the seller in the making of the sales contract, he sued for money damages. At the same time, however, he affirmed the validity of the contract and moved to deposit the remaining installments in the court’s registry to avoid the contract’s harsh forfeiture provisions. The Court of Appeals rejected this use of Rule 67: the plaintiff had no interest in the installments after he had affirmed the contract, so the deposits belonged to the seller and were not “in dispute.” GSU, unlike the buyer in Baxter, denies that it owes the deposits to Southern.11
GSU could have breached its contracts by and withheld money from Southern and the court, but we see no reason to force GSU to do so. We do not fault GSU for making deposits under Rule 67 as the district court decides those are proper.12 Admittedly, regardless of the outcome of this case, Southern will be entitled to be paid for gas already taken, but it is in the discretion of the district court under Rule 67 to decide how much of the payments from GSU should be held in the court. On this record, a partial release of these funds has not been adjudicated by the district court. The district court did not abuse its discretion.
Y. Intervention by the LPSC
As set out above, the district court denied the LPSC’s motion to intervene pursuant to Fed.R.Civ.P. 24. As we explain, a decision of this Court interpreting Rule 24 mandates that we reverse the district court and allow the LPSC to intervene.
Rule 24 provides:
(a) Intervention of Right. Upon timely application anyone shall be permitted to [1476] intervene ... (2) when the applicant claims an interest relating to the property or transaction which is the subject of the action and he is so situated that the disposition of the action may as a practical matter impair or impede his ability to protect that interest, unless the applicant’s interest is adequately represented by existing parties.
(b) Permissive Intervention. Upon timely application anyone may be permitted to intervene in an action ... (2) when an applicant’s claim or defense and the main action have a question of law or fact in common_In exercising its discretion, the court shall consider whether the intervention will unduly delay or prejudice the adjudication of the rights of the original parties.
The LPSC meets all of the requirements of Rule 24(a) and may intervene as of right. First, it filed a timely motion to intervene. Second, it has an interest in the GSU-Southern litigation. Louisiana law charges the LPSC to “investigate the reasonableness and justness of all contracts” made by GSU, and the LPSC may “disallow as an operating expense of [GSU]” any unreasonable payments GSU makes to Southern. La.Rev.Stat.Ann. § 45:1176 (West 1982). The LPSC is the only government party seeking to intervene, and it will have to determine whether GSU may pass-through to consumers the cost of its purchases from Southern. Third, the LPSC must intervene now to protect GSU’s customers, before the results of this litigation are res judicata. Finally, though the LPSC’s views of this case are not yet known, we cannot assume that GSU will represent the LPSC’s interests.
Our analysis of Rule 24(a) is controlled by New Orleans Public Service, Inc. v. United Gas Pipeline Co., 690 F.2d 1203 (5th Cir.1982) (“NOPSI 7”). In NOPSI I, we held that the mayor and city council members of New Orleans could intervene as of right in a suit between NOPSI and its gas supplier, because the intervenors had a “statutory obligation to oversee NOPSI’s fiscal and public responsibilities.” Id. at 1209. After deciding NOPSI I, we learned the law had been changed and that the LPSC — not the city officials — had been given the authority to regulate NOPSI’s rates, and we reversed NOPSI I. New Orleans Public Service, Inc. v. United Gas Pipeline Co., 694 F.2d 421 (5th Cir.1982) (“NOPSI II”).13 The case before us resembles the case we perceived in NOPSI I, and NOPSI I mandates that the LPSC may intervene as of right. Accord Mississippi Power & Light Co. v. United Gas Pipeline Co., 621 F.Supp. 718 (S.D.Miss.1985) (ordering intervention as of right under facts similar to NOPSI 7); cf. NOPSI I, 690 F.2d at 1216-17 (Garwood, J., concurring) (expressing “serious doubts” that the regulatory agency has an “interest” in the litigation).
In the alternative, we would hold that the district court abused its discretion by denying permissive intervention under Rule 24(b), especially because neither GSU nor Southern opposed the LPSC’s intervention or claimed that it would prejudice their rights or delay the litigation. See NOPSI I, 690 F.2d at 1209-10.14
[1477] VI. Conclusion
We affirm the district court’s exercise of subject matter jurisdiction subject to the limits discussed above. The district court may address GSU’s claims that Southern failed to renegotiate in good faith, that the UPS and Interchange contracts were induced by fraud, that Southern is selling more than its available Long Term Power under Schedule E, and that the quantity of electricity GSU must take under its contracts excuses its performance under state contract law. As the litigation proceeds and GSU’s theories become clearer, however, the district court may find that the FERC has exclusive or primary jurisdiction over some of GSU’s claims.
Until the district court decides the merits of this case, it may within its discretion accept deposits under Rule 67 from GSU. Finally, the motion of the LPSC to intervene should be, and is, granted.
The decision of the district court is
AFFIRMED IN PART, REVERSED IN PART, AND REMANDED.