Kerrygold Company and North Downs Dairy - both wholly-owned Irish Dairy Board subsidiaries - have merged to form Adams Foods.
The new company, whose key brands include Kerrygold butter and Pilgrim's Choice cheddar, becomes the UK's leading supplier of retail pre-packed hard cheese and of private-label convenience and healthy cheese.
The former Kerrygold and North Downs Dairy factories in Leek, Staffordshire; and Wincanton, Somerset; remain operational.