Coal India Limited (CIL) is an Indian central public sector undertaking under the ownership of the Ministry of Coal, Government of India. It is headquartered at Kolkata. It is the largest government-owned-coal-producer in the world. It is also the seventh largest employer in India with nearly 272,000 employees. The PSU contributes around 82% to the total coal production in India. It produced 554.14 million tonnes of raw coal in 2016–17, an increase from its earlier production of 494.24 million tonnes of coal during FY 2014–15 and earned revenues of from sale of coal in the same financial year. In April 2011, CIL was conferred the Maharatna status by the Government of India, making it one of the seven with that status. As of 14 October 2015, CIL is a PSU owned by the Central Government of India which controls its operations through the Ministry of Coal. As of 14 October 2015, CIL's market capitalisation stood at making it India's 8th most valuable company. CIL ranks 8th among the top 20 firms responsible for a third of all global carbon emissions. History Coal mining in India had primarily been a private sector enterprise. This changed in September 1956 when the Government of India established its own coal company National Coal Development Corporation (NCDC). Collieries run by the Railways formed the nucleus of NCDC. This was to fulfill the fast growing energy requirements in the country to support rapid industrialization taking place through Five-Year Plans of the Government. In the same year, Singareni Colliery Company, which was operating in Andhra Pradesh since 1920, was also brought under the Government control when the Central Government and state Government of Andhra Pradesh acquired 45% and 55% shares respectively. In 1971, the Government of India nationalized all the 214 coking-coal mines and 12 coke-ovens running in the private sector, excluding those held by TISCO and IISCO for their captive use. On 1 January 1972, a new Government company Bharat Coking Coal Limited (BCCL) was formed to take control of these nationalized mines and coke-ovens. On 30 January 1973, all the remaining 711 non-coking coalmines of the country in private sector were also nationalized. 184 of these mines were handed over to BCCL, and remaining 527 were handed over to a newly opened department Coal Mines Authority. 4 months later, on 14 June 1973, this department was converted into a separate Government company CMAL. NCDC, earlier