Operafund Eco-Invest SICAV plc & Anor v Spain [2025] EWHC 2874 (Comm)

<center><span class="news-text_italic-underline">Judgment Date: 10 November 2025</span></center>

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The English Commercial Court has refused an application to substitute an assignee as claimant in proceedings to enforce an ICSID Convention award. The court held that neither the ICSID Convention nor the Energy Charter Treaty (“<span class="news-text_medium">ECT</span>”) permits the assignment of arbitration awards and that registering an award under <span class="news-text_italic-underline">The Arbitration (International Investment Disputes) Act 1966</span> does not create a new, assignable right. An Australian judgment reaching the opposite conclusion did not create an issue estoppel preventing Spain from contesting assignability.

Background

OperaFund invested in renewable energy projects in Spain. Following legislative changes that removed certain incentives, OperaFund commenced ICSID arbitration under the ECT and obtained an award in 2019. The award was registered in England in 2021. Spain sought to set aside the registration on state immunity grounds; those issues remain stayed pending the UK Supreme Court’s decision in ISL v Spain.

OperaFund later purported to assign all rights under the award to Blasket, an investment fund. OperaFund and Blasket applied under CPR 19.2(4)(a) to substitute Blasket as the claimant in the English enforcement proceedings. Spain opposed substitution, arguing that ICSID awards cannot be assigned.

Issue Estoppel

OperaFund and Blasket argued that the Federal Court of Australia’s decision in <span class="news-text_italic-underline">Blasket (FCA)</span> — which held that ICSID awards were freely assignable—gave rise to an issue estoppel.

The English court rejected this for two reasons:

• <span class="news-text_medium">Not final and conclusive:</span> No sealed order had yet been issued in Australia.
• <span class="news-text_medium">Spain had not submitted to jurisdiction:</span> Under the <span class="news-text_italic-underline">Civil Jurisdiction and Judgments Act 1982</span>, foreign judgments against a state can only be recognised if the state submitted to the foreign court’s jurisdiction. Spain appeared solely to contest jurisdiction and therefore did not submit.

The judge also confirmed, contrary to Spain’s argument, that issue estoppel can arise from a foreign judgment on a pure point of law, provided the legal issue was fundamental to the foreign court’s reasoning.

Assignment Under the ICSID Convention and the ECT

No express provision in the ICSID Convention authorises or prohibits the assignment of awards. Applying Articles 31–32 of the Vienna Convention on the Law of Treaties, the Court held:

• The term “<span class="news-text_medium">a party</span>” in Article 54(2) refers only to parties to the original arbitration.
• ICSID’s structure, including the requirement to file a copy of the certified award, presupposes enforcement only by those original parties.
• Commentary and the absence of consistent state practice reinforced this interpretation.

Regarding the ECT, the Court found that Article 15’s specific treatment of subrogation implies a general prohibition on assignment. If assignment were freely permitted, Article 15 would be redundant. The Court concluded that the drafters could not have intended assignability to depend on the “random effects” of domestic law, which would produce inconsistent outcomes across jurisdictions.

Effect of Registration Under the 1966 Act

Registration of the award does not create new substantive rights. The 1966 Act is purely procedural and implements the UK’s obligations under the ICSID Convention. It cannot transform a non-assignable right under the Convention into an assignable one. The Court of Appeal’s decision in <span class="news-text_italic-underline">Micula v Romania</span> was applied. OperaFund can still pursue enforcement in its own name, while Blasket—under the assignment agreement—may control the process and receive any recovered sums.

Conclusion

This is a significant judgment with potential implications for the market in investment treaty awards, particularly for funders who treat such awards as tradeable assets. The Court’s approach diverges from <span class="news-text_italic-underline">Blasket (FCA)</span> and other international decisions, underscoring a developing split on whether ICSID awards may be assigned. Both OperaFund/Blasket and Spain are expected to pursue appellate options in England and Australia. The reasoning on issue estoppel, especially the confirmation that estoppel may arise on points of law, will also attract attention.