The 4 coal blocks that were spared are government-run, non joint ventures. Two of the exempted coal blocks are in Madhya Pradesh and two in Jharkhand. The apex court gave "six months" breathing time to the coal blocks that are already operational.

The 42 blocks  would till  then be managed by Coal India .The companies running these blocks also have to compensate the govt by paying Rs. 295 per metric tonne.

The court said the blocks have to go as the allotments were illegal and arbitrary.

This has come as a big blow India's top private and government companies in key industries - power, steel and cement.

The apex court had said last month the coal blocks were allocated "illegally and arbitrarily" since  by various regimes at the Centre on the recommendation of a bureaucrats' panel.

The court, which had condemned the procedures adopted by 36 screening committee meetings, however, had stopped short of cancelling them, saying, "what should be the consequences, is the issue which remains to be tackled".

The potential investments that may get affected together could top Rs. 2 lakh crore.

Companies that take a hit include Vedanta, Essar, Jindal Steel and Power, JSW, NTPC, SAIL and Hindalco, among others.

The government's top lawyer, attorney general Mukul Rohatgi, had told the court earlier this month that if all blocks are cancelled, state giant Coal India be allowed to take over active mines, or companies be allowed to continue production until the blocks are re-auctioned, in order to avoid supply disruptions.

States such as Jharkhand, Odisha, Chhattisgarh and Madhya Pradesh had written to the Centre, requesting it not to consider re-allocation of coal blocks in its suggestions to the court, as it would lead to escalation in the cost of mining. (PTI - HT)