The Coal Ministry has issued letters for de-allocation of eight coal blocks following the recommendations of the Inter-Ministerial Group. The Ministry sources said, among the companies affected by the de-allocation are Grasim Industries, Gujarat Ambuja Cement, Lafarge, Electrotherm and Kesoram Industries. The blocks were deallocated by the government as they were not developed within a stipulated timeframe and for which satisfactory explanations were not given.