Experts play a pivotal role in international arbitration, particularly in disputes involving complex technical or financial matters. Their core function is to provide objective, specialised opinions that help arbitral tribunals understand issues outside their expertise. Experts may be appointed either by the parties or by the tribunal, with each approach offering distinct benefits and drawbacks.
1. Introduction
Many international arbitrations often involve complex evidences which include highly technical issues. Therefore, the dispute to be decided by the arbitral tribunal may require particular knowledge in fields that the arbitrators are not sufficiently familiar with and where the arbitral tribunal may need assistance that might guide it in its search for the truth.
2. The role of an expert in any arbitral procedure
The primary duty of an expert is to assist the tribunal by delivering independent, impartial, and professionally sound opinions. Experts are not advocates and must act impartially. Also, they must acknowledge when a question falls outside their expertise. They may serve evidentiary purposes—clarifying disputed facts—or explanatory purposes—providing insight into complex but undisputed matters.
Key factors in choosing an expert include professional competence, communication skills, integrity, and credibility. Technical expertise is paramount. Civil law jurisdictions often favour tribunal-appointed experts, whereas common law systems typically rely on party-appointed experts. International arbitration trends toward party-appointed experts.
3. Advantages and disadvantages of a party-appointed expert
Advantages
Party-appointed experts are particularly effective in technically intensive sectors like construction or energy. They work closely with the legal team, have access to extensive project documentation, and tailor their reports to address case-specific issues. This proximity ensures efficient communication and integration of technical findings into the party’s legal arguments. Their professional reputation depends on the quality of their work, incentivising thorough analysis. This model also supports the party’s right to be heard, as the expert’s perspective directly reflects the case strategy.
Disadvantages
The main criticism is perceived bias—some experts are accused of shaping conclusions to favour the hiring party. They may refuse cooperation with the opposing expert, leading to irreconcilable differences in methodology or findings. Reports can become overly technical and grounded in conflicting assumptions, making evaluation difficult for arbitrators. Costs are often substantial and claimed as part of litigation expenses.
4. Advantages and disadvantages of a tribunal-appointed expert
Advantages
Tribunal-appointed experts are generally seen as more neutral, with a duty of independence comparable to that of arbitrators. Their reports tend to be balanced and less adversarial. Cost control is another benefit, as fees are managed by the tribunal and split between the parties. A single expert report can streamline proceedings and help produce a coherent decision.
Disadvantages
Parties have less control over the expert’s selection and scope of analysis. There is a risk that key issues will be overlooked or misunderstood, especially if the expert lacks detailed knowledge of the specific industry involved. Access to project documentation can be limited, as communication typically flows through the tribunal. Reports may also be less detailed than those from party-appointed experts.
5. The use of experts according to different international arbitration rules
Leading arbitral institutions—such as the ICC, IBA, SIAC, HKIAC, and CICA—explicitly regulate the use of experts.
- ICC Rules allow for both party-appointed and tribunal-appointed experts, requiring written reports and, where needed, hearings.
- IBA Rules impose strict independence requirements, mandate disclosure of methodology and data, and permit pre-hearing meetings between experts.
- SIAC and HKIAC rules permit both models and emphasise clarity in expert roles and evidence.
- CICA rules recently established the primary use of party-appointed experts. Appointment by the tribunal of experts requires consultation with the parties and inclusion of any divergent opinions in tribunal-appointed expert reports.
6. How can we overcome the disadvantages?
Several procedural mechanisms can address the limitations of party-appointed experts:
- Pre-hearing meetings – Experts meet before hearings to identify and narrow points of disagreement, clarify technical issues, agree on methods, and improve efficiency in evidence-taking. This process is recognised in Article 5(3) of the IBA Rules and recommended by the ICC Task Force.
- Witness conferencing – All relevant experts are questioned together, allowing arbitrators to directly probe reasons for disagreement and compare methodologies. This method, provided in Article 8(2) of the IBA Rules, promotes transparency and can help the tribunal form a clearer view.
- Cross-examination – Experts are questioned by the tribunal or opposing counsel to test the reliability of their opinions. While potentially time-consuming, it allows the tribunal to assess credibility and understand divergent findings.
- Neutral coordinator/facilitator – A mutually agreed or tribunal-appointed specialist organises expert work, promotes objectivity, and encourages consensus. This can also be done by a tribunal-appointed expert who works alongside party-appointed experts without influencing their conclusions.
- Expert teaming – The tribunal selects one expert from each party’s proposed list to form a team, combining independence with sector-specific knowledge. The team produces a joint report, then a final version after considering party comments.
- Joint expert reports – Even with party-appointed experts, tribunals may require a single report summarising areas of agreement and disagreement in common terms, making it easier to identify the basis for differing opinions.
7. Conclusion
Experts, whether appointed by parties or tribunals, are indispensable in international arbitration when technical complexity exceeds legal expertise. Party-appointed experts offer deep, case-specific insight but risk perceived bias. Tribunal-appointed experts bring neutrality and efficiency but may face limitations in access or specialisation.
The choice between models depends on the dispute’s nature, industry complexity, and procedural preferences. Hybrid approaches and procedural safeguards can balance advantages while mitigating weaknesses. Ultimately, a skilled and independent expert enhances the tribunal’s fact-finding process and supports a fair, well-reasoned award.
For additional information or personalised legal assistance in the field of international commercial arbitration, we invite you to contact the Sarbu Partners team at office@sarbupartners.ro.
