De Group started primarily as a transport organization engaged in supply and transportation of sand to the underground bunkers of collieries of Coal Mines. In the beginning of 70's, it had graduated to effective Open Cast Coal Mine Operators. However, after nationalization of Coal Mines in the year 1973 changed all equations pushing De Group to the verge of closure.

De Group endured the challenge and emerged as one of the leading Transporters and Coal Handling Contractors of Eastern Coalfields Ltd, SAIL, IISCO, P.W.D., Eastern Railway and other Public Sector organizations. The 90's and early 90's was a period of consolidation and horizontal expansion where, De Group acquired its own Fuel Station, Engineering & Automobile Workshop, Distributorship of Automobile Spares and Tyres and other allied business.

Till 90's De Group operated from their Registered Office at Ukhra in the heart of Raniganj Coal Belt where, Sri Balaram De still operates from.

From mid 90's, with the introduction into business and active efforts of Sri Balaram De's sons Sri Biswadeep De and Sri Sundeep De, De Group made rapid strides with its flagship organization being Coal Mines Associated Traders. They expanded beyond their core area and operation i.e. beyond District of Burdwan to other parts of West Bengal and gradually other areas of Eastern India and North East Area and also beyond core area of competence of transportation and coal handling to varied operations like Highway Engineering, Open Cast Mining, Civil Construction & Infrastructure Project, Railway Infrastructure and Electrical Installations.