Stellantis Auto SAS & Ors v Autoliv AB & Ors

A court or tribunal may direct a single joint expert even where the instructing parties have conflicting interests. Conflict is a material factor, but it is not a trump card. The governing exercise applies the overriding objective or equivalent governing principles, together with the duty to restrict expert evidence to that reasonably required to resolve the dispute. The court must assess all the circumstances, including whether separate evidence would materially assist the trial or whether one expert would effectively disable a party. Ordinary differences between expert models, assumptions or data do not by themselves establish separate schools of thought. Proportionality and the value of the claim matter, but just disposal is also vital.

The claimants brought cartel damages claims exceeding €734 million against the Autoliv and ZF TRW groups of occupant safety-system manufacturers. The Competition Appeal Tribunal directed the defendants to rely on a single joint competition-economics expert in its ruling reported at [2023] CAT 66. After the claim was amended and one defendant withdrew, the Tribunal refused to revisit that direction in [2024] CAT 27.

The defendants appealed. They argued that conflicts concerning apportionment, causation and the alleged umbrella effect of the cartels required separate experts as a matter of principle. The central issues were whether any material conflict existed in relation to the proposed expert evidence and whether the existence of such a conflict automatically required separate experts.

1. Disposition. Birss LJ dismissed the appeals. Arnold LJ and the Master of the Rolls agreed.
2. Applicable framework. The CAT approaches expert-evidence case management on the same foundations as the civil courts under Part 35 of the Civil Procedure Rules. Those foundations are a duty to restrict expert evidence to what is reasonably required, the expert’s overriding duty to the court or Tribunal, and the power to direct evidence from a single joint expert. The overriding duty existed at common law and applies in the CAT: National Justice Compania Naviera SA v Prudential Assurance Co Ltd (The “Ikarian Reefer”) [1993] 2 Lloyds Rep 68.
3. Governing test. A direction for a single joint expert is governed by the overriding objective, or the equivalent CAT governing principles, and by the duty to restrict expert evidence to that reasonably required to resolve the dispute. The case must be dealt with justly and at proportionate cost. The existence of a conflict of interest is material, but it is not an automatic bar. The court may direct a single expert despite a conflict where that is the proper case-management decision.
4. A party’s need for expert evidence does not itself justify separate experts. A separate expert may be required where the use of one expert would effectively disable a party from presenting or defending its case, but that disability must arise from the difference between separate experts and a single expert. The expert’s overriding duty may require an opinion adverse to the interests of the party instructing the expert.
5. The existence of more than one school of thought may justify separate experts, but this refers to a specific and established divergence of approach. The fact that experts might use different regression models or disagree about input variables does not, without more, establish multiple schools of thought. Proportionality is relevant but is not the only consideration. The just disposal of the case remains vital.
6. The Court distinguished UK Trucks Claim Limited v Stellantis NV & Others [2023] EWCA Civ 875. That decision concerned divided loyalty within one class representative organisation. It did not establish the broad proposition that any conflict between parties in an econometric case requires separate experts.
7. Here, the defendants’ positions were mutually consistent. Any future contribution dispute did not presently affect the undifferentiated claim based on joint and several liability, and sales attribution involved facts rather than expert opinion. The overcharge evidence was incapable of distinguishing the individual cartels, and the available data could not separate the relevant nine-month period. There was therefore no material conflict in relation to the expert evidence.
8. The Tribunal’s reasons for limiting the defendants to one joint economics expert were compelling because separate experts would create multiple competing models and a disproportionate increase in disputes for the Tribunal to resolve. The Tribunal made no error of law. The appeals were dismissed.

1. Court of Appeal (Civil Division) — in [2024] EWCA Civ 609, dismissed the defendants’ appeals.
2. Competition Appeal Tribunal — in [2024] CAT 27, refused the defendants’ application to revisit the single-joint-expert direction.
3. Competition Appeal Tribunal — in [2023] CAT 66, directed the defendant groups to rely on a single joint competition-economics expert.