The group's four largest companies -- flagship Grasim, aluminium major Hindalco, fertiliser and copper maker Indo Gulf and Indian Rayon -- together consume around 1.4 lakh tonnes of coal per month, a significant portion of which is imported.

Senior officials of the group said that centralising coal imports has become essential as over the last two years, the proportion of imported coal has been rising considerably.

The Aditya Birla group's strategy cell has also advised that the newly acquired Shree Digvijay Cement's jetty in Gujarat, which has a capacity to handle over one million tonnes, can be used for coal imports. This will also reduce logistics costs significantly.

Grasim's senior executive president and head ofoperations Chandra Prakash Jajoo told The Financial Express: "We traditionally have been importing large quantities from South Africa. The group may enter into a long-term contract with one of the South African companies.

"We are also considering certain proposals that we have received from Chinese and Malaysian companies. The group will take a final decision on the issue soon."

Jajoo said that there was a strong possibility that a South African company could be the major supplier as the freight cost, in that case, will be the least.

Though the cost of imported coal, at Rs 2,600 per tonne, is around Rs 500 per tonne higher than Coal India's supplies, Jajoo said that imported coal is of much better quality and has lower ash content.

Indigenous coal has around 35-40 per cent ash content, and gives 3,500-4,000 kilo calories per kg, imported coal has an ash content of around 15 per cent and gives 6,500 kilo calories per kg.

As a result, the cost per million kilo calories comes to around Rs 525for indigenous coal, while it is around Rs 400 for imported coal, thus making it actually cheaper, Jajoo explained.

Most of the businesses that the group is in, like cement, aluminium, copper and carbon black, have a high requirement of coal. At the same time, most of the group's captive power plants, like the 613mw capacity for Hindalco's Renukoot smelter and Birla Copper's facility at Dahej in Gujarat, are coal-fired.

Grasim, Jajoo pointed out, currently imports around 90 per cent of its coal requirement for the Vikram Cement unit, its largest with a capacity of 2.5 million tonnes.

The individual companies had been entering into import deals with local importing agents. By entering into coal-supply agreements directly, the group will also be able to cut down on the commission expenses.