Asia's largest oil refiner China Petrochemical Corp, parent of listed China Petroleum & Chemical (Sinopec), signed a memorandum of understanding with the world's largest oil producer Saudi Aramco. The firms will invest in a proposed oil refining plant in Yanbu, a city on Saudi Arabia's west coast. CPC will hold 37.5 per cent of the Red Sea Refining projecvt company and Saudi Aramco 62.5 per cent.