An arbitral award is usually expected to bring a dispute to an end. Within the European Union, however, an award against a Member State or a public entity may open an entirely new front: whether its payment or enforcement would amount to unlawful State aid under Articles 107 and 108 of the Treaty on the Functioning of the European Union (“TFEU”). This question has become particularly prominent in intra-EU investment arbitration, most notably through the Micula litigation and, more recently, the European Commission’s decision in Antin.[1]
The issue is not limited to investment arbitration. It may also arise in commercial disputes whenever the performance of a contract, a settlement or the satisfaction of an award involves State resources and confers an advantage that would not have been available under ordinary market conditions. In such cases, the fact that a claimant has established a contractual or treaty entitlement does not necessarily mean that the resulting payment can lawfully be made within the EU legal order.
EU State aid law does not give Member States or State-owned entities a general defence to arbitration, nor does it automatically invalidate an arbitration agreement. Its effect is more practical, and often more disruptive. It may affect the enforceability of the underlying obligation, limit the relief available to the tribunal, justify a stay while the Commission considers the measure, require the recovery of sums already paid and, ultimately, prevent an otherwise valid award from being recognised or enforced within the European Union. The award may therefore settle the dispute between the parties while leaving unresolved the separate question of whether EU law permits its economic consequences.
Aid, Unlawful Aid and Incompatible Aid
Article 107(1) TFEU applies where a measure is attributable to a Member State and financed through State resources, confers a selective economic advantage on an undertaking, distorts or threatens to distort competition and is capable of affecting trade between Member States.[2] All of those conditions must be satisfied.
Arbitration pleadings often use three distinct State aid concepts interchangeably:
- “Aid” describes a measure falling within Article 107(1);
- “Unlawful aid” is new aid implemented in breach of the notification and standstill obligation in Article 108(3);
- “Incompatible aid” is aid that the European Commission has decided cannot be approved for the internal market.
That division of responsibility matters in practice: only the Commission can decide whether aid is compatible with the internal market, while national courts and, where necessary, arbitral tribunals must still consider whether the measure constitutes aid and whether it was implemented in breach of the standstill obligation.[3]
The first consequence of a breach is generally that the measure must be stopped or reversed, rather than treated as automatically void. A court may have to prevent implementation, order recovery, preserve the position through interim measures or award damages to an injured competitor.[4] A tribunal faced with the same EU-law problem should not assume that a valid contract under the governing national law can simply be performed as written.
Commercial Arbitration and EU State Aid: The Market Economy Operator Test
In commercial cases, the State aid issue usually arises upstream. A public authority or State-controlled company may have sold an asset below market value, granted an unusually favourable guarantee, waived a debt, accepted an improvident settlement or promised a tariff that a private operator would not have offered. The central question is whether the public party behaved as a rational private operator would have done in comparable circumstances.
The litigation between the Greek electricity producer DEI and its industrial customer, now Metlen, is the clearest illustration. In 2024, the Court of Justice rejected the proposition that an arbitral tribunal operating under the Greek energy regulator’s framework could simply be assimilated to an ordinary State court, with the result that its award was automatically attributable to Greece. The potentially relevant State measure was DEI’s voluntary decision to conclude the arbitration agreement.[5] On remittal in November 2025, the General Court upheld the Commission’s finding of no aid: referring the tariff dispute to arbitration was conduct that a prudent private electricity supplier could reasonably have adopted.[6]
This provides an important counterweight to the broader approach taken in investment arbitration. An award involving a State-owned enterprise does not become State aid simply because the company is publicly controlled, has lost the case or must satisfy the award using public resources. The real question is whether, at the time, the decision to contract, arbitrate or settle was one that a rational private operator could also have taken on the information then available. Arbitration is inherently uncertain, and an unfavourable outcome does not retrospectively turn an otherwise commercial decision into State aid.
For counsel, the practical point is to build the record at the time the decision is made. Valuations, board materials, external advice, the alternatives considered and a realistic assessment of litigation risk may later matter far more than how the transaction was described. Where a public entity cannot explain, with contemporaneous evidence, why its decision made commercial sense, the arbitration itself may come to be treated as part of the alleged aid.
Damages Are Not a Safe Label
Nor does describing an award as one for “damages” place it beyond State aid scrutiny. In Asteris, the Court of Justice held that compensation payable by public authorities for damage they caused does not, as such, constitute aid.[7] Genuine compensation restores the claimant to the position it would have occupied absent the wrong; it does not necessarily confer a selective advantage.
The substance matters more than the label. A claimant should not be able to recover, in the form of damages, the value of aid that was never notified or approved. The same applies where an award of expectation damages or specific performance would effectively restore the preferential treatment that EU law required the State to remove.[8] The key question is, therefore, what the award is really compensating for. Is it making good an ordinary commercial loss, or is it preserving an advantage that would not have existed under normal market conditions?
The answer may also shape the relief available. Depending on the circumstances, the tribunal may have to refuse specific performance, limit recovery to a market-based amount, separate the lawful part of the claim, issue a partial award or pause the proceedings while the Commission considers the measure. What it cannot do is assume for itself that the aid is compatible with the internal market.
Micula: When Payment of an Award Becomes State Aid
Micula moved the debate from the underlying transaction to the award itself. Romania had withdrawn regional tax incentives before joining the EU.[9] An ICSID tribunal later awarded compensation to Swedish investors under the Romania-Sweden BIT. In 2015, the Commission concluded that payment of the award would recreate the economic advantage conferred by the withdrawn incentives and would therefore constitute incompatible State aid. It ordered Romania not to make further payments and to recover sums already paid.[10]
The Court of Justice held in 2022 that the alleged aid was granted when the right to compensation crystallised in the 2013 award, after Romania’s accession, so the Commission had temporal competence to review it.[11] On remittal, the General Court in October 2024 upheld the Commission’s decision. That judgment is under appeal in Case C-890/24 P.[12]
The enforcement proceedings were just as significant. In Commission v. United Kingdom, the Court of Justice held that the UK had breached EU law when its Supreme Court authorised enforcement of the Micula award without respecting the standstill obligation, the Commission process and the duty of sincere cooperation.[13] The practical consequence is that enforcement remains subject to State aid law, even where the award is binding under the ICSID Convention.
Antin: From Controlling Payment to Controlling the Award Itself
The Commission’s 2025 Antin decision goes further. The underlying ICSID award ordered Spain to compensate two investors for changes to its renewable-energy support regime. The Commission found that the award, and in any event its implementation, entailed incompatible State aid. Its reasoning treated Spain’s consent to the intra-EU arbitration framework, and any later decision to recognise, enforce or pay the award, as attributable State conduct; it also focused on the economic effect of restoring the investors’ expected preferential remuneration.[14] Spain was directed not to pay and to ensure that no payment was made.[15] The investors have challenged that decision before the General Court in Case T-365/25.[16]
Antin should not be taken to mean that every award of damages against an EU Member State amounts to State aid. The decision arose from a particular set of circumstances, namely intra-EU investment arbitration, the autonomy of EU law and compensation connected to a regulated support scheme.[17] It nevertheless increases the risks at the post-award stage. In cases of this kind, State aid law is not limited to challenging the tribunal’s jurisdiction. It may also prevent the award from producing its intended legal and economic effects after it has been rendered.
How EU State Aid Can Affect the Arbitration Process
First, tribunals should be alert to potential State aid issues from the outset. They may arise where the dispute involves a public counterparty, a State guarantee, preferential pricing, debt relief, regulated tariffs, a settlement unsupported by an independent valuation or damages tied to a withdrawn subsidy. Where the point is genuinely in issue, the tribunal should invite submissions from the parties rather than raise and decide it on its own.
Second, the tribunal should separate existence from compatibility. It may analyse Article 107(1), notification, block exemptions and the standstill obligation. It should not purport to authorise aid on policy grounds reserved to the Commission. Where a Commission investigation is pending, a stay or staged decision may be preferable to an award whose performance would immediately breach Article 108(3).
Third, enforceability deserves attention before the award is drafted. Ordinary consensual tribunals cannot generally refer questions directly to the Court of Justice under Article 267 TFEU, while the national courts supervising annulment or enforcement can do so.[18] Eco Swiss also shows that fundamental EU competition rules may enter award review through public policy.[19] State aid objections are therefore likely to reappear at the seat, at the enforcement forum or in parallel proceedings.
The Amsterdam proceedings concerning AES Solar and Ampere Equity Fund provide a concrete illustration. In an interlocutory judgment of 29 May 2024, the Amsterdam District Court held that Spain’s claims concerned the enforcement of EU State aid rules, rather than proceedings to annul or enforce the awards. In its final judgment of 5 February 2025, the court held that Spain’s payment obligations under the awards constituted State aid and ordered the investors, conditionally, to repay any amounts subsequently received through payment or enforcement.[20] That creates a procedural reality which arbitration counsel cannot ignore: the award may be only one front in a wider dispute involving national courts and the Commission.
Finally, payment is not always the end. Unlawful and incompatible aid can be recovered with interest.[21] A beneficiary that has collected an award may consequently face repayment proceedings, while the Member State may face infringement action if its courts or authorities facilitate payment contrary to EU law.
Conclusion
EU State aid law rarely determines whether an arbitral tribunal can hear a dispute. Its real impact is felt later, when the tribunal considers whether the underlying arrangement can be performed, what relief can lawfully be granted and whether the resulting award can be paid or enforced.
In commercial arbitration, the central question is usually whether the public entity acted as a private market operator would have acted when entering into the contract, settlement or arbitration agreement. In intra-EU investment cases such as Micula and Antin, the focus may shift to the award itself, or to its payment, as the alleged aid measure. In either context, tribunals should confront the issue directly, distinguish genuine compensation from the restoration of a selective advantage and consider from the outset how the standstill obligation may affect both the remedy and the enforcement of the award.
[1] Antin Infrastructure Services Luxembourg S.à r.l. and Antin Energía Termosolar B.V. v Kingdom of Spain, ICSID Case No. ARB/13/31 (“Antin”); European Commission, Commission Decision (EU) 2025/1235 of 24 March 2025 on the measure State aid SA.54155 (2021/NN) implemented by Spain: Arbitration Award to Antin (notified under document C(2025) 1781) OJ L, 2025/1235, 25 June 2025.
[2] Consolidated Version of the Treaty on the Functioning of the European Union [2012] OJ C326/47 (TFEU), Art. 107(1).
[3] Consolidated Version of the Treaty on the Functioning of the European Union [2012] OJ C326/47 (TFEU), Art. 108(3); European Commission, Notice on the enforcement of State aid rules by national courts (2021/C 305/01), OJ C 305 (30 July 2021), p. 1, paras. 11-13 and 56-57.
[4] European Commission, Notice on the enforcement of State aid rules by national courts (2021/C 305/01), OJ C 305 (30 July 2021), p. 1, paras. 71-72, 75-77 and 85-99.
[5] Mytilinaios AE – Omilos Epicheiriseon v. Dimosia Epicheirisi Ilektrismou AE (DEI) and European Commission; European Commission v. DEI, Joined Cases C-701/21 P and C-739/21 P, Judgment (22 February 2024), ECLI:EU:C:2024:146, paras. 92-113.
[6] Dimosia Epicheirisi Ilektrismou AE (DEI) v. European Commission, Joined Cases T-639/14 RENV II, T-352/15 RENV and T-740/17 RENV, Judgment (12 November 2025), ECLI:EU:T:2025:1017; P. Nicolaides, Arbitration Decision that is Free of State Aid, 2 December 2025.
[7] Asteris AE and Others v. Hellenic Republic and European Economic Community, Joined Cases 106/87 to 120/87, Judgment (27 September 1988), ECLI:EU:C:1988:457, paras. 23-24.
[8] European Commission, Notice on the enforcement of State aid rules by national courts (2021/C 305/01), OJ C 305 (30 July 2021), p. 1, paras. 97-99.
[9] See also Aceris Law, Enforcement of the Micula ICSID Award Rejected, 28 July 2022.
[10] European Commission, Decision (EU) 2015/1470 of 30 March 2015 on State aid SA.38517 (2014/C) (ex 2014/NN) implemented by Romania – Arbitral award Micula v. Romania of 11 December 2013, OJ L 232 (4 September 2015), p. 43, Arts. 1-2.
[11] European Commission v. European Food SA and Others, Case C-638/19 P, Judgment (25 January 2022), ECLI:EU:C:2022:50, paras. 123-145.
[12] European Food SA and Others v. European Commission, Joined Cases T-624/15 RENV, T-694/15 RENV and T-704/15 RENV, Judgment (2 October 2024), ECLI:EU:T:2024:659; European Food SA and Others v. European Commission, Case C-890/24 P, Appeal brought (19 December 2024), OJ C, C/2025/1411 (10 March 2025).
[13] European Commission v. United Kingdom, Case C-516/22, Judgment (14 March 2024), ECLI:EU:C:2024:231.
[14] European Commission, Decision (EU) 2025/1235 of 24 March 2025 on State aid SA.54155 (2021/NN) implemented by Spain – Arbitration award to Antin, OJ L, 2025/1235 (25 June 2025), recitals 187-193 and 218-219.
[15] European Commission, Decision (EU) 2025/1235 of 24 March 2025 on State aid SA.54155 (2021/NN) implemented by Spain – Arbitration award to Antin, OJ L, 2025/1235 (25 June 2025), Art. 2.
[16] Infrastructure Services Luxembourg and Energia Termosolar v. European Commission, Case T-365/25, Action brought (3 June 2025), OJ C/2025/4061 (28 July 2025).
[17] Slovak Republic v. Achmea BV, Case C-284/16, Judgment (6 March 2018), ECLI:EU:C:2018:158; Republic of Moldova v. Komstroy LLC, Case C-741/19, Judgment (2 September 2021), ECLI:EU:C:2021:655.
[18] Nordsee Deutsche Hochseefischerei GmbH v. Reederei Mond Hochseefischerei Nordstern AG & Co. KG, Case 102/81, Judgment (23 March 1982), ECLI:EU:C:1982:107, paras. 10-13; D. Chochitaichvili and L. Kengen, ‘Les tribunaux arbitraux et la Cour de justice de l’Union européenne : un dialogue impossible ? Réflexions autour du renvoi préjudiciel’, 2025(1) b-Arbitra 26, pp. 26-59.
[19] Eco Swiss China Time Ltd v. Benetton International NV, Case C-126/97, Judgment (1 June 1999), ECLI:EU:C:1999:269, paras. 35-37; C. Liebscher, A. Komninos and M. Kamvysi, “European Law”, in C. Liebscher (ed.), The Healthy Award in International Commercial Arbitration (2nd edn., Kluwer Law International 2023), §§ 2.04-2.05.
[20] Kingdom of Spain v. AES Solar Energy Coöperatief UA and Ampere Equity Fund BV, Rechtbank Amsterdam, Case C/13/728512 / HA ZA 23-64, Judgment (29 May 2024), ECLI:NL:RBAMS:2024:3156, paras. 4.11-4.24.
[21] European Commission, Notice on the recovery of unlawful and incompatible State aid (2019/C 247/01), OJ C 247 (23 July 2019), p. 1, paras. 11-13 and 69-72.
