The master-plan of the metro corridor was made in 1971 along with the North–South Corridor, connecting the office district of Bidhannagar with the twin city and transportation hub Howrah via another transport hub of the city, Sealdah, and the central business district Esplanade by an underwater metro line. It is a project, sanctioned in 2008 by Prime Minister Manmohan Singh. The foundation stone was laid on 22 February 2009 and construction started in March 2009. The autonomous Kolkata Metro Rail Corporation (KMRC) was formed to implement the project. The Government of India (Ministry of Urban Development) and Government of West Bengal each had a half-share in it. Later, the Government of West Bengal pulled out from it, and the shares were transferred to the Ministry of Railways.