Japan's Mitsui & Co and Saudi Arabia's Nabaa Industrial Development and Investment Co are considering building a $20 billion petrochemical complex in Yanbu, an industry source said. Both companies will take a final investment decision when they complete feasibility studies by June this year, the source told Reuters at a mining exhibition in Jeddah, on the Red Sea coast. “The feasibility has to prove if the project is viable,” he said. The complex would use crude oil as feedstock and is expected to produce 45 petrochemical products, he added. The project, if feasible, would be operational by 2019, the source who declined to be identified said. The complex would have a capacity of “several million tons” of petrochemicals. Saudi Arabia aims to boost petrochemical output to 80 million tons per year in 2015 from 60 million tons.