Zama, however, said the unions would keep resisting any move that could undermine the position of Coal India.
India will allow locally registered foreign firms to mine and sell coal when commercial mining is permitted as part of the opening up of the nationalised industry after four decades, Coal Secretary Anil Swarup told Reuters.
India's steel imports from China, the world's biggest producer of the alloy, doubled in April-September from a year ago though the country has enough capacity to meet its demand.
Prime Minister Narendra Modi's decision to open commercial coal mining to private players is a key step towards bringing order to the country's chaotic power industry and ending the chronic blackouts that impede its economic rise.
Diesel makes up nearly half of fuel demand in Asia's No 3 economy.
These refineries, commissioned mostly in the 1950s and 1960s during India's early industrialisation push, are inefficient and costly to maintain compared to their modern counterparts on the coast mainly operated by private companies.
This is perhaps the first time that retail prices in India are higher than the global rates
The company has also advised power firms to use trucks to carry coal from remote mines, like the Amrapali open cast pit in eastern Jharkhand state.
Reliance Industries has sought environment ministry approval for a $13 billion upgrade to its Jamnagar complex, including a 400,000 barrels per day (bpd) refinery.
There was a sharp fall in power output on Thursday from a plant in Gujarat that left India more than 9,000 megawatts short of peak demand, according to two officials at the state grid operator.
In the long run, the decision could bring clearer rules to a sector that has failed to provide India with enough power because it has been so hamstrung by confusion and scandals over concessions allegedly handed to government cronies.
The government will decide in August whether to sell a 5 percent stake in ONGC, a senior oil ministry official said, in a deal that would be worth $2.9 billion at current market prices.
State behemoth Coal India, the world's largest coal miner, has failed to raise its output fast enough to meet demand, and millions of Indians still go without power.
The comment was in response to a June 19 Reuters story citing sources with knowledge of the matter as saying that India planned to clear some oil payments to Iran through the United Arab Emirates central bank.
Finance Minister Arun Jaitley presents his maiden budget next month and faces headwinds from a weak economy, a food inflation scare and now the risk that higher oil prices could swell the government's oil subsidy bill.
India on Tuesday set a minimum export price for onions of $300 per tonne to discourage overseas shipments amid an inflation scare that threatens to stoke public anger over rising prices at local food markets.
The panel, however, set some conditions for the company, including that Cairn India will have to upload the status of environment compliance, including results of monitored data, on its website and update it periodically.
The PM-elect wants to fix the coal sector; cut coal imports by boosting output.
Jindal Steel and Power and JSW Steel, are in competing talks to buy parts of insolvent Italian steelmaker Lucchini.
The shutdown of the gasoline making units would result in the production of high sulphur gasoline that cannot be sold in India.