LONDON, June 7 (Reuters) – Global payments processors Visa (V.N), opens new tab and Mastercard (MA.N), opens new tab must face a new set of lawsuits over fees charged to retailers, after a London tribunal ruled on Friday that collective cases brought on behalf of merchants can proceed.

The two firms already face a long list of lawsuits in London over multilateral interchange fees, which retailers pay when consumers use a card to shop.

Visa and Mastercard are each being sued by hundreds of claimants at London’s Competition Appeal Tribunal, which is managing the various cases together.