Can the winner of an ICSID award sell it to a buyer who then enforces it in England? Not on the basis of the voluntary assignment in this case, held the Court of Appeal on 2 November 2026 in Operafund Eco-Invest SICAV plc v Kingdom of Spain [2026] EWCA Civ 1392. Foxton LJ, with whom Males and Lewison LJJ agreed, dismissed the appeal of the assignee, Blasket Renewable Investments LLC, against the decision of HHJ Pelling KC (paras 3, 162–163, 167). Whether the state’s consent would allow an assignee to enforce was left open (paras 137, 166).
What the case was about
Spain offered generous incentives for renewable energy from 1997, then substantially amended the regime between 2010 and 2014, prompting 51 known arbitrations under the Energy Charter Treaty (“ECT”) (paras 4–5). Two investors incorporated in Malta and Switzerland chose arbitration under the ICSID Convention and obtained an award of €29.3m in 2019 (para 6). The award was registered in England under the Arbitration (International Investment Disputes) Act 1966 in September 2021, and Spain applied to set the registration aside (para 7). Spain’s annulment application at ICSID was rejected in March 2023 (para 8).
In January 2024 the investors purported to assign all their rights under the award to Blasket (para 10), a Delaware company incorporated to acquire and exploit investment treaty awards (para 16). Blasket applied to be substituted for the investors in Spain’s set-aside application, which required it to prove a valid assignment (para 11). The judge refused, holding that only a party to the arbitration could seek registration and enforcement under Article 54(2) of the ICSID Convention, and that registration under the 1966 Act could not make the award assignable (para 13).
What the Court of Appeal decided
No general power to assign investors’ treaty rights without state consent. The court held that the assignability of the ICSID award was governed by international law and was not devolved by the Convention to national law (paras 46, 147, 153). On the current state of customary international law, treaty rights between states cannot be assigned without the obligor state’s consent (para 59). There is not yet the substantial uniformity of state practice, or the general recognition by states, needed for a rule treating investors’ treaty rights differently (paras 61, 75). The court would not “develop” international law by adopting a rule not accepted by states to the degree customary international law requires (para 78). An ICSID award exists on the international law plane, so the rights asserted in enforcing it are treaty rights (para 96). Blasket’s argument from the absence of any prohibition in international law also failed: it had to show not merely that assignment was not prohibited, but that it was legally effective to change Spain’s obligations without Spain’s consent (para 91).
Foxton LJ said that, after that conclusion, the remaining treaty grounds were not strictly necessary to decide, but addressed them because they had been fully argued (para 99).
The ECT point went the other way, but did not matter. If international law had recognised a general power to assign, the court was not persuaded that Article 15 of the ECT, on state subrogation, would have excluded it (paras 100, 112).
Only a party can enforce under Article 54(2). “A party” seeking recognition or enforcement most naturally means one of the parties bound by the award under Article 53 (para 133). The court agreed with the judge that only a party to an ICSID award can seek recognition and enforcement under Article 54(2) (para 137). It was not enough that the investors had started the process: a party “seeking” recognition and enforcement does so throughout, and Blasket’s intervention was itself an attempt to seek enforcement (para 138).
Registration does not create a separately assignable right. Section 2(1) of the 1966 Act does not create a right that can be assigned under English law independently of the award (para 152). Whether an award can be assigned is not a question of enforcement or execution devolved to each enforcement state (paras 147, 153). Allowing the right to enforce to be assigned separately would risk the award being enforced by different people in different countries, an attempt to “divide the indivisible” (paras 157–159).
The court acknowledged that its decision differs from first-instance decisions in the United States and Australia and an interim decision in the Netherlands, describing the divergence as “highly unfortunate” (paras 137, 164). Males LJ said it was the court’s duty to decide the issue for itself (para 164).
Why it matters
- A setback for the award-trading market. In England, a voluntary assignee of an ICSID award, where the original award creditor still exists, cannot rely on the assignment to enforce the award itself; whether the state’s consent would change that was left open (paras 59, 137, 152).
- The original creditor stays in the picture. The judge had noted that, subject to Spain’s set-aside application, the investors could still enforce, with Blasket controlling the process and recovering proceeds under the assignment agreement (para 116).
- The type of award may matter. The court indicated, without deciding, that awards made on the municipal law plane, such as seated UNCITRAL awards, may raise different issues (paras 95–96).
- Questions left open. Transfers on insolvency or death, corporate succession where the original rights-holder ceases to exist, and assignments the state consents to were left for a case in which they arise (paras 137, 165–166).
- In our view, anyone buying or financing investment treaty awards should now treat the arbitral forum as a central due-diligence question, and watch for the Australian Full Court’s judgment in the parallel Blasket case, which the court was told is expected in January 2027 (para 67).
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Read the full judgment: Operafund Eco-Invest SICAV plc v Kingdom of Spain [2026] EWCA Civ 1392 (The National Archives).