Union minister and Dravida Munnetra Kazhagam leader Murasoli Maran died at the Apollo Hospital in Chennai on Sunday evening, his family sources said.
Maran, 69, a minister without portfolio in the Cabinet, is survived by his wife, two sons and a daughter. The cremation will be held on Monday.
The ailing leader was flown on November 14, 2002, to the Methodist Hospital in Houston, Texas, for treatment of his heart, kidney and other vital organs. He had been in coma for many weeks. He was brought back to India and admitted to the Apollo Hospital in September this year.
The DMK announced a week's mourning to condole his death.
Prime Minister Atal Bihari Vajpayee said it was a personal loss for him.
Commerce and Industry Minister Arun Jaitley said, "We deeply mourn the passing away of Maran. He will be remembered as a statesman and politician of outstanding calibre."
His contribution in the field of commerce and industry was immense, Jaitley said, adding Maran left an indelible impression after he stoutly defended India's interests at the Doha round of the World Trade Organisation negotiations.
Karnataka Chief Minister S M Krishna said Maran had set exemplary standards in public life. His contributions as Union minister, particularly in the Ministry of Commerce and Industry, were significant, he added.