Public sector oil firms IOC, BPCL, HPCL and EIL will pool their resources to invest Rs 1.5 lakh crore in setting up India's biggest refinery on the west coast, Oil Minister Dharmendra Pradhan said. Indian Oil Corp (IOC), the nation's biggest refiner, will build a 60-million tonne a year oil refinery in Maharashtra along with Bharat Petroleum Corporation Ltd (BPCL), Hindustan Petroleum Corporation Ltd (HPCL) and Engineers India Ltd (EIL), Pradhan said in a twitter post. "Refinery to be built in 2 phases (40 plus 20 million tonnes); the first phase will have more than Rs 1 lakh crore investment (biggest in India)," he said. IOC has been looking at the west coast for a refinery as catering to customers in West and South was difficult with its refineries mostly in the North. HPCL and BPCL have also been looking at a bigger refinery because of constraints they face at their Mumbai units.