Vitchanan Photography/Shutterstock Save for later Print Download Share Swiss registered Varo is set to become one of the world’s top-five Sustainable Aviation Fuel (SAF) and Hydrotreated Vegetable Oil (HVO) producers overnight following its Mar. 31 purchase of Swedish refiner Preem from Saudi-Ethiopian magnate Mohammed Hussein al-Moudi's Corral Holdings. Varo is two-thirds owned by US private equity giant Carlyle Group and one-third by Swiss trading giant Vitol. It will become the largest refinery co-processor of renewable feedstocks in Europe and the region’s second-largest producer of renewable fuels behind Finland’s Neste.