Chennai Petroleum Corporation Limited was originally founded in 1965 as Madras Refineries Limited (MRL) and was a subsidiary of Indian Oil Corporation until 1987, when both companies were converted into separate public sector units. The holding company of the group, Indian Oil Corporation (IOCL), holds a majority stake in the company. In 1995, Chennai Petroleum Corporation Limited (CPCL) was formed by merging three Madras Refineries Limited (MRL) and two Indian Oil Corporation facilities located in various cities in Tamil Nadu.
