New Delhi, May 30 -- For the last 50 years, Nusli Wadia has been corporate India's ultimate samurai-an uncompromising patrician who never backed down from a fight. Armed with an enviable pedigree, an aristocratic spine and a legendary temper, he built the Wadia Group, whose antecedents trace back to 1736, into a diversified Indian conglomerate.

He has looked the part too, with piercing eyes and an immaculate sartorial presence. But at 82, the legendary corporate warrior who spent a lifetime defying the odds finds himself in the winter of his life, presiding over a group with revenues of roughly $2.7 billion that, for all its historical heft, is no longer among the country's largest conglomerates.

The pedigree itself is almost impossibly...