Chennai Petroleum Corporation Limited, formerly known as Madras Refineries Limited, is a subsidiary of Indian Oil Corporation Limited which is under the ownership of Ministry of Petroleum and Natural Gas of the Government of India. It is headquartered in Chennai, India. It was formed as a joint venture in 1965 between the Government of India, Amoco and National Iranian Oil Company, having a shareholding in the ratio 74%: 13%: 13% respectively. From the grassroots stage CPCL Refinery was set up with an installed capacity of 2.5 million tonnes per year in a record time of 27 months at a cost of ₹430 million without any time or cost overrun. Wikipedia