Draft Arbitration Rules of PMAC: the Arbitrator Selection and Challenge Process

On 4 June 2025, the Patent Mediation and Arbitration Centre (the Centre) of the Unified Patent Court (UPC) launched a (now closed) public consultation to solicit feedback on its Draft Arbitration Rules (the Draft Rules). Building on our previous analysis of the Draft Rules, this blog post focuses specifically on the arbitrator selection and challenge process: how it works under the Draft Rules, how it compares to other arbitral regimes, and what implications it may carry for parties seeking technical expertise, flexibility, and fairness in patent-related disputes.

The Power of Choice: Why Arbitrator Selection Matters

Arbitrator selection is not just a procedural formality – it is a key decision. The ability of parties to choose their decision-makers is one of arbitration’s most valued features: it fosters trust in the process and outcome, especially in high-stakes patent disputes. These often turn on specialised subject matters, ranging from life sciences and pharmaceuticals to telecoms, software, and AI, and parties depend on arbitrators with sector-specific expertise to ensure outcomes that are both legally and technically sound.

The Centre’s Arbitrator List

Like several other specialised commercial institutions or subject-specific panels of the World Intellectual Property Organization (WIPO), the Centre intends to maintain a public list of arbitrators (the Arbitrator List) from which parties may appoint. According to the Centre’s director, Aleš Zalar, the Arbitrator List will feature professionals from all 18 UPC member states as well as key jurisdictions worldwide, including the US, China, Japan, Korea, and India. The Arbitrator List will be jointly established by the Centre’s director and the Centre’ expert committee, composed of 12 experts in the field of patent, mediation, arbitration law (the Expert Committee). 

Parties conducting arbitration under the Draft Rules “may” choose arbitrator candidates from the Arbitrator List (Art 12(5)) but also remain free to nominate other candidates. Any nomination will, however, need to be confirmed by the Centre (Art 13). Such confirmation process is standard and provided for by many of the most commonly used arbitration rules (eg ICC, LCIA). Parties should thus avoid nominating candidates who are manifestly unsuitable to determine a patent arbitration dispute.

In this context, the Centre’s director has clarified that such nominees must meet the very same selection criteria used to vet arbitrators for inclusion on the Arbitrator List. These criteria are set out in a 5-page draft proposal document prepared by the Expert Committee following internal consultations (the Selection Criteria). Echoing the Centre’s director, the Selection Criteria’s preamble explicitly states that both “accredited arbitrators” and “arbitrators who are not accredited but are nominated by parties” must “meet or exceed” the criteria, which require, among other things, that arbitrators have at least five years’ relevant legal experience, appropriate technical expertise, or applicable business and industry experience. 

The Draft Rules themselves contain no express reference to these substantive restrictions (other than echoing the Selection Criteria’s general requirement of independence and impartiality in Art 12(1)). Rather, on their face, the Draft Rules give parties broad autonomy, particularly by not limiting appointments to the Arbitrator List. There is a requirement in Art 12(4) that arbitrators are “duly qualified”, but, as currently drafted, this applies only to appointments by the Centre, and not to its confirmations of parties’ arbitrators. 

If the Centre indeed intends to introduce a vetting role for the Centre and subject party autonomy to a degree of institutional oversight, the Draft Rules might benefit from incorporating this feature more clearly, given the departure from the greater flexibility typically associated with other commercial arbitration institutions

The Appointment Process

The appointment and challenge procedures are set out in Arts 12-16 of the Draft Rules, which emphasise fairness, independence, and transparency from the outset.

Art 13(1) provides that tribunals may consist of a sole arbitrator or three members, depending on the arbitration clause or the parties’ agreement. If the clause is silent, the Centre decides, with the default being a sole arbitrator unless three are “necessary based on the circumstances” (generally due to value or complexity) (Art 13(2)). This default mirrors the approach under the WIPO and International Chamber of Commerce (ICC) arbitration rules.

Even more important than tribunal size will likely be the question of who is appointed. As with other rules, the chair (or sole arbitrator) may be jointly agreed by the opposing parties or their arbitrators; indeed, this is the primary appointment method. However, this step often proves contentious in practice given parties’ divergent preferences.

If the parties or their arbitrators fail to agree on the chair or sole arbitrator, or a party fails to nominate its own arbitrator when due, the Centre circulates a shortlist of at least three candidates for strike-and-rank to the parties. Having received the parties’ expression of preference (ie the ranking and striking of the proposed arbitrator candidates), the Centre then proceeds to appoint an arbitrator from that shortlist (Art 13(3)(ii), 13(5)(ii), and 13(5)(iv)). If this process fails, the Centre appoints directly at its discretion (Art 13(3)(iii)). The Draft Rules are silent on whether these arbitrators proposed or directly appointed by the Centre must come from the Arbitrator List. If the Centre exclusively appoints from the Arbitrator List in practice, this may provide some predictability but could also constrain unaligned parties by limiting them to a list that, however curated, cannot capture the full diversity of expertise in fast-moving fields such as AI, semiconductors, or biotech.

Either way, the strike-and-rank process preserves a measure of party autonomy when consensus breaks down. By contrast, most major institutions (like the London Court of International Arbitration (LCIA) and ICC) appoint chairs or sole arbitrators directly where parties are deadlocked, with only a few prominent exceptions, notably American Arbitration Association’s International Centre for Dispute Resolution (AAA-ICDR) and WIPO, also using a strike-and-rank process. By embedding this strike-and-rank procedure, the Draft Rules establish a strong default in favour of party choice.

Multi-Party Disputes

Where there are multiple claimants or respondents, they must jointly nominate their respective arbitrator in three-member tribunals (Art 14). In many patent disputes, joint nomination will not pose problems, as co-claimants are often affiliated or joint patentees, and co-respondents may belong to the same group of companies. But in complex cases such as enforcement campaigns by multiple patent pool members or cases spanning entire supply chains, interests can diverge; notably among co-respondents. 

Should co-parties fail to agree on their arbitrator, the Draft Rules provide a robust solution by empowering the Centre to restore party equality by appointing arbitrators for "one or both" sides (Art 14(ii)). In doing so, the Centre circulates names for a strike-and-rank procedure. This particular procedural feature is fairly unique: most commercial rules do not provide for strike-and-rank at all, and the few that do, such as the WIPO rules, only do so for chair or sole arbitrator selection and not for multi-party nominations. 

By extending the mechanism to co-party appointments, the Draft Rules again preserve a degree of party engagement even when consensus breaks down.

Challenges

Arbitrators may be challenged where there are “justifiable doubts” as to independence or impartiality (Art 15); this language is consistent with the language proposed in the UNCITRAL Model Law on International Commercial Arbitration and major rules such as those of the LCIA or WIPO. However, the Draft Rules’ UPC context and IP focus mean that conflicts may extend beyond the usual ties to counsel or repeat appointments and also arise from, for example, prior litigation or advocacy work, parallel case involvement, or recurring issue conflicts such as repeat FRAND/SEP expert work and party-side patterns (see here for our discussion of the Draft Rules’ effect on FRAND/SEP disputes). It is therefore likely that the Centre’s Expert Committee will develop its own distinct jurisprudence on what constitutes 'justifiable doubts', creating a body of precedent that is tailored to the specific quandaries of patent law.

Parties must notify the Centre of a challenge within 15 days of appointment or of discovering the grounds therefore; a requirement which enhances efficiency and is consistent with most leading rules. As with many other major rules such as WIPO and the German Arbitration Institution (DIS), the tribunal has discretion to suspend or continue proceedings while a challenge is pending.

Similar to many other arbitral rules, the challenges are decided by a neutral third party. Where the Draft Rules diverge from most other institutions is that challenges are decided by the abovementioned Expert Committee composed of “experts in the field of patent law and mediation and arbitration law who support the Centre” (Art 15(7) and Art 1), as opposed to by a secretariat (ie an institution’s administrative arm) or court (ie an institution’s standing decision-making body). The reason for this may be that challenges in patent disputes can, beyond the standard independence issues, also hinge on alleged technical bias, such as prior advocacy in FRAND/SEP litigation, strong published views on the scope of protection for pharmaceutical patents, or close ties to sector-specific litigation – just to name a few examples. In such cases, review by a body with combined patent and arbitral expertise will enhance decision making and lend decisions additional credibility. The Centre’s decision to create this specialised, dual-function body is therefore structurally sophisticated, though its success will, as always, hinge on the appointment of well-regarded experts who can command the confidence of the user community.

Following its review, the Expert Committee will issue a reasoned and final decision to the parties (Art 15(7)). In this manner, the Centre will be offering additional transparency, more than, for example, WIPO, which often issues decisions without reasons, though less than the LCIA, which publishes anonymised summaries of challenges. The Centre may, of course, wish to consider matching the LCIA’s standard by also committing to publish anonymised summaries of its challenge decisions, thereby building institutional precedent and enhancing user trust. 

Key Takeaways

The Draft Rules strike a pragmatic balance between party autonomy and institutional safeguards. The curated, but non-exclusive, Arbitrator List helps parties source the right technical expertise without unduly constraining nominations; though further clarification from the Centre regarding the criteria applicable to arbitrators outside the Arbitrator List would be welcomed. The expanded use of strike-and-rank (including for multi-party nominations) and the role of the Expert Committee for challenges are standout features that differentiate the Centre from other institutions and may offer useful value-add to parties. 

Freshfields stands ready to assist stakeholders with tailored guidance on navigating complexities under the Draft Rules, including the selection of arbitrators and the management of appointments and challenges.

Note: All references to rules refer to the versions of the rules in force at the time of publication.