Complex sentence: Carr's Flour Mills and agricultural supplies business are owned by Carr's Milling Industries plc still based in Carlisle, and have recently appeared in UK supermarkets through their Carr's Breadmaker flour range.
Split into simpler sentences: Carr's Flour Mills and agricultural supplies business are owned by Carr's Milling Industries plc, which is still based in Carlisle. Its products have recently appeared in UK supermarkets through their Carr's Breadmaker flour range.