India: Tata becomes India's wealthiest group
India's Tata Group has become the country's wealthiest, with a market value higher than the combined wealth of the two Reliance conglomerates.
The combined value of the Reliance groups, led by feuding brothers Mukesh and Anil Ambani, is $81.6bn.
The Tata group, led by Ratan Tata, is worth $98.7bn (£60.9bn), according to the company.
The change is partly the result of the strengthening share prices of the almost 30 listed Tata companies.
These firms are in a range of industries from energy to chemicals.
But it is also due to the fall in the market value of the Ambani brothers' firms over the past year.
The Reliance group of companies has faced challenging times as a company riven by family feuds and disputes.
Run by Mukesh Ambani's brother Anil, the telecoms company has faced a slump in its share prices as a result of a high profile scandal involving licences for second generation phones.
Tata's elevation to India's most valuable quoted company indicates a marked reversal from a year ago in the fortunes of the Tata and Reliance groups, the BBC's Nidhi Dutt in Mumbai (Bombay) says.
Despite having many more companies listed on the Indian stock exchange in 2010, Tata ranked behind Mukesh Ambani's Reliance Industries, which held the top slot. Reliance has interests in the petrochemical and energy sectors, but only two listed firms.
But one year on, Tata is now not only worth more than Reliance Industries, but both it and Reliance Communications combined.