Sainsbury's Supermarkets Ltd v Mastercard Incorporated & Ors

Disclosure of documents obtained from a competition authority’s file requires a case-by-case balancing exercise. The court must weigh the claimant’s interest in obtaining relevant evidence, including whether the information is available elsewhere, against confidentiality, business secrecy, anonymity, and the public interest in effective competition enforcement. Relevant and otherwise unavailable material may justify disclosure. Protective measures should be imposed where necessary, including an opportunity for the authority to comment, review by external lawyers, and disclosure initially within a limited confidentiality ring.

MasterCard applied for an order requiring disclosure to Sainsbury’s of documents supplied by the European Commission following MasterCard’s access to the Commission’s file in an ongoing investigation into inter-regional interchange fees. The documents arose from a pilot study and the Deloitte Survey concerning the merchant indifference test. They were relevant to expert evidence in Sainsbury’s damages proceedings and were unavailable from another source. The application was unopposed, but raised issues concerning confidentiality, merchant anonymity, and the possible effect of disclosure on the Commission’s investigation and future competition enforcement.

1. The application was granted in principle. The court applied a case-by-case balancing exercise, weighing the interests of the claimant in obtaining relevant documents against the protection of confidential information, business secrets, third-party interests, and the public interest in effective competition enforcement. The approach reflected Donau Chemie AG (Case C-536/11) and the considerations identified in Pfleiderer.

2. The documents’ relevance to an important issue was a strong factor favouring disclosure. Their unavailability from any other source was a powerful additional factor.

3. The interests of the participating merchants appeared sufficiently protected because the Commission had anonymised the material and taken steps to protect business secrets and confidential information. Assuming that the Commission had honoured its confidentiality obligations, disclosure would not adversely affect the ongoing investigation, future investigations, or the willingness of commercial bodies to assist the Commission.

4. Disclosure was nevertheless subject to safeguards. The Commission was to receive an opportunity to comment before the order took effect. MasterCard’s external legal team was first to review the documents for any matter undermining the protection of merchants’ confidential interests. Initial disclosure was to be limited to necessary members of the existing confidentiality ring, including external lawyers and potentially experts. Wider disclosure required a further application.

5. The parties were directed to prepare a draft order reflecting those safeguards for the court’s approval.