Billionaire Ambani brothers in legal showdown

The two have drafted India's top lawyers to argue a case over gas supplies that pits the country's biggest private sector company Reliance Industries Ltd, led by Mukesh Ambani, against Reliance Natural Resources Ltd, headed by Anil.

A Supreme Court bench led by Chief Justice K.G. Balakrishnan is due to hear the case in which billions of dollars are at stake.

The row stems from a family pact splitting the Reliance assets after the 2002 death of their father Dhirubhai, who built a corporate colossus that straddled India's economy from telecommunications to energy.

The case involving the nation's richest gas field was expected to get underway in the Supreme Court at around 0830 GMT.

Anil, 50, is demanding the honouring of a 2005 settlement brokered by their mother that would allow Reliance Natural Resources to buy gas from Reliance Industries at 44 percent below the government-set rate.

Mukesh, India's wealthiest man, insists the 17-year deal needed government approval and that the government price -- set after the family settlement was agreed -- must prevail.

Anil, 50, made a failed bid this month to patch things up with his brother, with whom he has had a slew of disputes over issues including a proposed blockbuster telecom deal last year that Mukesh tried to block.

But Mukesh, 52, rebuffed his overtures, saying the issues needed to be settled by the court and the dispute was "not merely a family matter" but one that involved Reliance Industries' shareholders.

The government has intervened in the case, asserting its right to set gas prices. It argues that the gas from the Krishna-Godavari Basin belongs to the nation and cannot be sold at cut-rate prices.

Anil has accused the petroleum ministry, whose minister was a friend of their father, of "blatantly and openly supporting" Mukesh in his "unlawful design" to get out of the deal to supply gas from the field in the Bay of Bengal.

Reliance Industries shares were down 18.2 rupees or 0.82 percent at 2,206.5 rupees ahead of the hearing. Reliance Natural Resources was up 2.2 rupees or 2.53 percent at 89.05 rupees.

The dispute has focused attention on government intervention in India's energy pricing.

Anil has blamed the quarrel for poor international investor response to a recent government auction of rights to explore for hydrocarbons in the Bay of Bengal.