J Sainsbury Plc, the British grocer caught up in a cost-cutting war with its supermarket rivals, sought to prevent secrets of how it sets its prices from being revealed to competitors as part of an industry-wide lawsuit over credit-card fees.

The retailer is among more than a dozen companies, also including Marks & Spencer Group Plc and units of Arcadia Group, that are suing Visa Inc. in London over transaction fees for using its credit and debit cards. But a lawyer for Sainsbury said it won’t agree to airing its pricing details in open court, fearing senior executives may reveal useful information for rivals.

These secrets “are the crown jewels,” Sainsbury’s lawyer Mark Brealey said during a court hearing on Tuesday. “There’s no way we would be in the same trial as Morrisons or Asda where details of pricing are revealed while competitors sit in the back row."

Pricing information is particularly sensitive in the supermarket industry, as traditional big supermarkets seek to mark down goods to stop customers deserting to discounters Aldi and Lidl. Sainsbury’s said earlier this month it’s replacing its so-called “Brand Match” promotion with lower regular prices on products like chicken, bread and cheese.

The lawsuit targeting Visa could hinge on whether the retailers raised prices to cover the fees, effectively handing them on to customers, lawyers said. In order to establish that, senior executives must be questioned on how much they pay for goods, and how they then price them for sale.

While it’s common for claimants and defendants to disagree over how a case may proceed, it is “most troubling” that the retailers themselves are unable to agree, Judge Stephen Phillips said.

Lawyers for Visa, Arcadia and M&S said they are in favor of having a joint trial where relevant sections of the lawsuit are heard in private.

Executives from the companies must leave the court and only the lawyers would remain said Paul Lowenstein, a lawyer representing M&S and a dozen units of Arcadia Group.

“The reins must be very tightly drawn so there is no leakage,” he said.

Subscribe Now

Authoritative analysis and perspective for every segment of the payments industry

14-Day Free Trial

Authoritative analysis and perspective for every segment of the industry