Find an Arbitrator

Adamakopoulos v Cyprus May Provide Blueprint for 'Mass Claims' in Investment Arbitration

by Simon Maynard

November 2020

Simon Maynard

This blog post was originally published on the Practical Law Arbitration Blog and is reproduced with the permission of Thomson Reuters.

Claims brought by more than one investor are not unusual in the investor-state context, even where the claims are brought by claimants of different nationalities under several treaties. However, such claims have typically emanated from one investment operation, such as where a single claim is brought by joint venture partners in relation to their respective shareholdings in the same special purpose vehicle.

This changed dramatically with the advent of a series of claims arising from Argentina’s 2001 sovereign debt default. In each of Abaclat, Ambiente and Alemanni, a multitude of Italian bondholders sought to bring investment treaty claims against the state to obtain redress for their losses. Each of these cases settled before the issuance of an award of liability. Now, a case brought by nearly 1,000 claimants against the Republic of Cyprus may finally provide a blueprint for the conduct of so-called “mass claims”.

Adamakopoulos v Cyprus

The claimant group is comprised of 951 Cypriot nationals, six companies incorporated in Cyprus and one additional claimant incorporated in Luxembourg. All are either bondholders or shareholders of one of two local banks: the Cyprus Popular Bank (also known as Laiki Bank) and the Bank of Cyprus.

Between 2012 and 2013, both banks incurred heavy losses stemming from the Greek financial crisis. In response, in March 2013, Cyprus agreed a plan with the European Commission, the European Central Bank and the International Monetary Fund, which involved the merger of the two banks. Depositors with either bank holding assets in excess of USD100,000 received a haircut on their assets.

The claimants argue that these actions caused Laiki Bank bonds to become worthless. As for Bank of Cyprus bonds, these were converted into equity in the bank, which the claimants also allege now has no value.

In 2015, the claimants commenced arbitration under the Cyprus-Greece bilateral investment treaty (BIT) and Cyprus-Belgium/Luxembourg BIT.

A single “dispute”?

On the question of jurisdiction, the tribunal disagreed with the Abaclat tribunal that it was insufficient to conclude merely that “there is jurisdiction over the individual claims”. Instead, in keeping with Alemanni, the tribunal found that rather than a “myriad of separate disputes”, there must be a single “dispute” within the meaning of the BITs.

Whereas in Alemanni the tribunal opted to join its determination of this question to the merits (which then settled before a decision on liability was rendered), in Adamakopoulos the tribunal addressed this issue in its decision on jurisdiction.

In support of its position that the claim was not a single dispute, Cyprus observed that the claimants relied on two different BITs, held different types of assets, in different banks, and had invested at different times. However, the tribunal (by a majority) determined that there was nevertheless a “substantial unity” of claims, since “all of the claims are about the measures that were taken against the two banks, which in key respects are identical measures”. For the tribunal, furthermore, the claim “was about the treatment of foreigners and all claimants fall into that class” and “the standard for determining liability is essentially the same under both BITs”. Accordingly, the tribunal concluded that the claims could be considered together as a “single dispute”.

Compatible with the ICSID framework?

Having concluded that it had jurisdiction over the dispute, the tribunal then opined that the “real source of concern”, which led “to doubts about its characterisation as a single dispute” was “the number of claimants”. This, the tribunal observed, was principally an issue related to the manageability of mass claims within the ICSID framework, and thus one of admissibility, not jurisdiction.

In this regard, the tribunal was “not convinced” by the Abaclat tribunal’s conclusion that it could make use of its procedural powers to impose a “simplified examination process”, which may entail a “diminution of rights” for the parties. The tribunal considered that the general power to decide on procedural matters, as set out in article 44 of the ICSID Convention, “does not provide a mandate for a tribunal to invent its own procedural framework”.

Instead, the question was whether the arbitration could be managed within the existing ICSID framework. The tribunal found that it could, since “each stage of the process” could be “conducted in a manner that preserves the rights of the parties”. Thus, the tribunal considered the mass claim to be admissible, subject to certain conditions.

As regards those conditions, notably the tribunal observed that Cyprus had raised legitimate concerns regarding the practicability of collecting on a potential cost award in favour of Cyprus. The tribunal therefore decided that “it would be a reasonable protection of the respondent’s interests to make an order for security of costs and condition the continuance of this case on the provision of that security”. The tribunal invited Cyprus to make such an application within 30 days.


This case confirms that, in principle, investment treaty arbitration is amenable to so-called mass claims, including where they are brought by claimants of different nationalities, under more than one treaty and in relation to different investments. However, Adamakopoulos, like Alemanni before it, suggests that the claimants in such cases will have to convince the tribunal that the claims in question nevertheless amount to a single dispute. In addition, it seems that the tribunal will have to be satisfied that, despite the potential additional complexities introduced by large numbers of claimants, the claim can be fairly administered without compromising the parties’ procedural rights. If Adamakopoulos reaches an award on the merits, we may finally see a blueprint for how such claims may be administered in practice.


Simon Maynard resolves complex commercial disputes under English and international law. He has particular expertise in international commercial and investment treaty arbitration, with a focus on disputes concerning upstream oil and gas, renewables and the energy transition, and the TMT sector. Simon has been recognized by Euromoney as a "Rising Star" for international arbitration from 2018-2020. 


Additional articles by Simon Maynard
The views expressed by authors are their own and do not necessarily reflect the views of Resourceful Internet Solutions, Inc., or of reviewing editors.

Arbitration News

Med-Arb: Is It the Wave of the Future?The pressure on the Alternate Dispute Resolution world to handle what I believe will be a dramatic increase in volume offers the opportunity to consider a third or hybrid process of dispute resolution known as ...more
Arbitration in the Mix Regarding Mining Dispute in Zambia Reuters reported that Zambia’s state mining arm ZCCM-IH plans to appeal a court ruling in favor of India-based Vedanta, which has sought arbitration in a dispute over its jointly owned copper mine that is facing liquidation. Vedanta and th ...more
Tesla Owner's Bid to Avoid Arbitration in Battery Dispute Fails The Ninth Circuit Court of Appeals has dashed a Tesla owner’s plea to avoid arbitration regarding a battery dispute. Prior, a trial court ruled that Tesla I ...more
A Rare Occurrence: California Court Overturns Arbitrator's AwardEmployers should review their NDA agreem ...more
What law governs your arbitration clause? You decide. It will probably surprise you to hear that this is an issue that has vexed the courts and commentators, in England and internationally, for many years. ...more
Arbitration agreements: Governing law United Kingdom November 6 2020 - Clarification has recently been given by the Supreme Court in Enka v Chubb Russia [2020] UKSC 38, on the principles to be applied to determine the proper law of an arbit ...more
One more reason to arbitrate: BC's new Arbitration Act Arbitration has become an increasingly popular method for resolving legal disputes traditionally dealt with through the court system. Arbitration is known to be far more efficient and c ...more
London Court of International Arbitration (LCIA) Issues New Arbitration Rules The London Court of International Arbitration (LCIA) issued its new arbitration and mediation rules on Oct. 1, 2020. These rules will apply to all arbitrations commenced after ...more
Updates to ICC Arbitration Rules Aim for More Efficient, Flexible and Accountable Arbitrations On October 6, 2020, the International Court of Arbitration to the International Chamber of Commerce (ICC) adopted updates to its Rules of Arbitra ...more