Can an investor assign the benefit of an ICSID award, and may the assignee seek recognition and enforcement in its own name? On 30 September 2026, the U.S. District Court for the District of Columbia, in Blasket Renewable Investments LLC v. Kingdom of Spain (No. 25-cv-1756), held that Article 54(2) of the ICSID Convention does not preclude an assignee from seeking enforcement of a validly assigned award. The judgment of the Court of Appeal of England and Wales in OperaFund Eco-Invest v. Spain, delivered on 2 November 2026, reached a different conclusion in proceedings concerning Blasket’s proposed substitution for the original award creditors. The decisions concern the same OperaFund/Schwab award and assignee, but arose in different procedural settings.

1. Background: from Spanish renewable-energy incentives to U.S. enforcementPROCEDURAL BACKGROUND

Beginning in 1997, Spain enacted legislation offering financial incentives for renewable-energy investment. According to the U.S. Memorandum Opinion, legislation adopted between 2012 and 2017 reduced and ultimately withdrew incentives on which the relevant investors had relied. The resulting disputes led to ICSID arbitrations under the Energy Charter Treaty (ECT). (U.S. Memorandum Opinion, pp. 3–4.)

The U.S. proceedings concerned three ICSID awards in favour of OperaFund/Schwab, STEAG and Renergy. The principal damages awards were approximately EUR 29.30 million, EUR 27.675 million and EUR 32.896 million, respectively—approximately EUR 89.87 million in total, excluding interest and additional costs or amounts awarded in related decisions. The original award creditors subsequently assigned their rights under the awards to Blasket Renewable Investments LLC (Blasket). Blasket petitioned the District Court to enforce the awards on 3 June 2025. (U.S. Memorandum Opinion, pp. 4–8.)

On 12 December 2025, Spain moved to dismiss Blasket’s petition under Rules 12(b)(1), 12(b)(2) and 12(b)(6) of the Federal Rules of Civil Procedure or, alternatively, to stay the case. On 29 June 2026, the U.S. Supreme Court denied Spain’s petition for a writ of certiorari in related litigation (No. 24-1130). On 30 September 2026, Judge Randolph D. Moss issued a Memorandum Opinion rejecting Spain’s motion and stating that the Court would enter judgment for Blasket in the amounts and currencies specified in the awards. The Opinion stated that a separate order would issue. (U.S. Memorandum Opinion, pp. 8, 28–29; Supreme Court docket No. 24-1130.)

2. The U.S. court’s analysis of Spain’s objectionsMEMORANDUM OPINION · 30 SEPTEMBER 2026

2.1 Can an assignee seek enforcement under Article 54(2) and Rule 17?

Spain contended that a party seeking recognition or enforcement in Article 54(2) referred exclusively to a party to the underlying ICSID arbitration. Since Blasket had not participated in those arbitrations, Spain argued that it could neither enforce the awards nor rely on the ICSID Convention and its U.S. implementing legislation to establish federal jurisdiction.

Judge Moss rejected Spain’s construction. Article 54(2) requires a person seeking recognition or enforcement to furnish a copy of the award certified by the ICSID Secretary-General; the provision does not expressly confine that person to an original party to the arbitration. Looking at the Convention’s context-dependent use of party, and drawing on Blue Ridge Investments, LLC v. Republic of Argentina, the Court held that the Convention does not bar an assignee from enforcing a validly assigned ICSID award. The Court then addressed the jurisdictional and procedural consequences of that conclusion. (U.S. Memorandum Opinion, pp. 11–14.)

• Subject-matter jurisdiction: 22 U.S.C. §1650a(b) gives federal district courts exclusive jurisdiction over proceedings to enforce ICSID awards; Spain’s objection based on non-assignability failed. The Court also noted the FSIA arbitration exception and controlling D.C. Circuit precedent in NextEra.
• Personal jurisdiction: Spain challenged personal jurisdiction only insofar as subject-matter jurisdiction was absent, so that argument failed as well.
• Real party in interest: As assignee of all three awards, Blasket was the real party in interest and a proper plaintiff under Federal Rule of Civil Procedure 17.

2.2 Full faith and credit: can EU-law objections reopen the awards?

Article 54(1) of the ICSID Convention obliges Contracting States to recognise awards as binding and enforce their pecuniary obligations. In the United States, 22 U.S.C. §1650a(a) directs that those obligations be enforced with the same full faith and credit as if the award were a final judgment of a state court of general jurisdiction. Applying the D.C. Circuit’s decision in Valores Mundiales, S.L. v. Venezuela, Judge Moss considered whether the tribunals’ jurisdictional determinations had been fully and fairly litigated and finally decided, whether the awards were authentic, and whether they remained binding within the ICSID system. The awards satisfied that deferential standard. (Memorandum Opinion, pp. 14–15.)

Spain argued that the tribunals had manifestly exceeded their authority and infringed the competence of EU institutions over intra-EU disputes and State aid. It relied on Blinder, Robinson & Co. v. SEC to seek an exception to the full-faith-and-credit obligation. The Court declined to extend that narrowly framed exception to permit a collateral attack on these ICSID awards. Spain clarified that it was not asking the Court to relitigate the tribunals’ jurisdictional determinations. Judge Moss accordingly found no need to decide whether the tribunals had in fact intruded upon EU institutional competences. This was a ruling about the permissible scope of review in U.S. enforcement proceedings, not a decision invalidating EU law. (Memorandum Opinion, pp. 15–20.)

2.3 International comity and foreign sovereign compulsion

Spain submitted that compliance with the awards could place it in breach of EU State aid law and urged the Court to refuse enforcement on grounds of international comity and the foreign sovereign compulsion doctrine. Judge Moss distinguished those doctrines from the obligation to enforce an ICSID award: neither was available to resolve a conflict between U.S. and EU regulatory laws, because the case did not involve applying U.S. regulatory law extraterritorially. Nor could comity displace the obligations embodied in the ICSID Convention and 22 U.S.C. §1650a. Relying in part on Micula v. Romania, the Court rejected Spain’s reliance on EU-law obligations as a defence to enforcement. It did not purport to decide whether payment of the awards would comply with EU State aid law as a matter of EU law. (Memorandum Opinion, pp. 20–24.)

2.4 The act of state doctrine

Spain also invoked the act of state doctrine, which generally prevents U.S. courts from passing on the validity of a foreign sovereign’s public acts within its own territory. Judge Moss held that the doctrine did not apply because the requested enforcement did not require the Court to declare any EU measure or European Commission decision invalid. The Court was being asked to give effect to the awards, not to adjudicate the validity of EU State aid measures. (Memorandum Opinion, pp. 25–26.)

2.5 The alternative request for a stay and the relief ordered

In the alternative, Spain asked the Court to stay the case pending proceedings before the D.C. Circuit and the U.S. Supreme Court. The Supreme Court had already denied certiorari in the related case (No. 24-1130), removing one asserted basis for delay. Spain also failed to show that awaiting other pending D.C. Circuit appeals would materially advance judicial efficiency or present a sufficiently serious legal question. The Court therefore rejected both dismissal and a stay, granted Blasket’s petition, and stated that judgment would be entered for the amounts awarded. Because the parties had not adequately briefed the appropriate exchange rate, it declined to convert the awards’ euro-denominated components into U.S. dollars. A separate order was to follow. (Memorandum Opinion, pp. 26–29.)

3. The U.S.–UK divide: one award, one assignee, different proceduresA COMPARISON OF U.S. AND ENGLISH COURTS

The most direct comparison concerns the OperaFund/Schwab award and Blasket as its purported assignee. In Washington, D.C., Blasket sought entry of judgment on that award together with the STEAG and Renergy awards. In England and Wales, the OperaFund/Schwab award had already been registered, and Blasket sought substitution for the original claimants under CPR 19.2(4)(a). These are related—but procedurally distinct—questions. (U.S. Memorandum Opinion, pp. 1, 11–14; High Court judgment [1]–[2].)

3.1 The U.S. approach: Article 54(2) does not exclude an assignee

The U.S. District Court treated Article 54(2) as a provision governing the submission of a certified award for recognition or enforcement. Its interpretation of a party was broad enough to include an assignee of a validly assigned award. Judge Moss also held that Blasket satisfied Rule 17’s real-party-in-interest requirement. The Opinion did not undertake the English Court of Appeal’s separate customary-international-law analysis of a general power to transfer treaty-based award rights. (U.S. Memorandum Opinion, pp. 11–14.)

3.2 The English approach: customary international law, Article 54 and registration

On 10 November 2025, the High Court of Justice of England and Wales (Commercial Court), in OperaFund Eco-Invest SICAV Plc & Anor v Kingdom of Spain [2025] EWHC 2874 (Comm), refused Blasket’s application to be substituted as claimant. HHJ Pelling KC concluded that the ICSID Convention did not permit the voluntary assignment at issue and that registration under the Arbitration (International Investment Disputes) Act 1966 did not create a separate English-law right capable of assignment. The judge did not identify a customary-international-law rule establishing either general assignability or general non-assignability, treating the case primarily as one of construing the Convention. (High Court judgment [54], [71] and [73]–[79].)

On 2 November 2026, the Court of Appeal of England and Wales dismissed the appeal in OperaFund Eco-Invest SICAV Plc & Ors v Kingdom of Spain [2026] EWCA Civ 1392. Lord Justice Foxton held that the award rights arose on the international-law plane and that the materials did not establish a general customary-international-law power enabling an investor, without the award-debtor State’s consent, to assign those rights with legal effect against that State. The issue was not merely whether international law prohibited assignment, but whether an assignment could legally alter the State’s obligation to pay a particular creditor. (Court of Appeal judgment [59]–[61], [89]–[96].)

On the separate treaty-construction question, the Court of Appeal agreed that a party in Article 54(2), read with Articles 53 and 54, ordinarily refers to an original party to the ICSID award. It expressly reserved cases involving involuntary succession or a transfer with the debtor State’s consent. The Court also held that assignability is anterior to enforcement or execution and is not delegated to the law of the enforcement forum by Article 54(3). Under section 2(1) of the 1966 Act, registration gives an ICSID award the force and effect necessary for execution; it does not create a free-standing English-law right of enforcement that can be assigned independently of the award. Importantly, the Court did not find it necessary to determine the exact boundary between enforcement and execution under the Convention. (Court of Appeal judgment [128]–[137], [146]–[153], [165]–[166].)

3.3 The source of the divergence—and its limits

The difference is not merely semantic. The U.S. District Court asked whether Article 54(2) barred Blasket, as assignee, from pursuing enforcement, and concluded that it did not. The English Court of Appeal asked the anterior question whether international law gave the purported assignment legal effect against Spain, and separately construed Article 54(2) as limiting the ordinary class of applicants. The two decisions therefore differ both in their approach to the source of the transferred right and in their reading of the Convention’s enforcement mechanism. (U.S. Memorandum Opinion, pp. 11–14; Court of Appeal judgment [91], [130]–[137].)

The Court of Appeal acknowledged differing first-instance or interim decisions in the United States, Australia and the Netherlands, but regarded them as insufficient to establish a settled international consensus. It did not decide whether an award might pass by operation of law—for example, on insolvency, death or corporate succession—or whether a transfer approved by the award-debtor State would enable the transferee to invoke Article 54(2). The decision should not, therefore, be described as an absolute prohibition of every form of transfer of ICSID award rights. (Court of Appeal judgment [137(i)]–(iii), [164]–[166].)

4. ConclusionCLOSING OBSERVATIONS

The decisions illustrate an unresolved question in the application of the ICSID Convention: when an investor assigns the benefit of an award, what legal basis permits the assignee to require performance from the award-debtor State and to invoke Article 54 in national courts? The U.S. District Court and the English Court of Appeal reached different conclusions in related proceedings involving the OperaFund/Schwab award. For cross-border enforcement, the binding character of an ICSID award, the identity of the person entitled to invoke it, and the subsequent availability of execution against sovereign property remain distinct issues.