Tata Sons, the holding company of the group, has hiked stake in Tata Steel by converting 1.2 crore warrants into equal number of shares for Rs 712.8 crore.
"Tata Sons vide their letter dated January 20, 2012 has exercised the option to convert 1.2 crore warrants into ordinary shares of the company at a price of Rs 594 per share," Tata Steel said in a regulatory filing to the BSE.
As on December-end, Tata Sons' stake in Tata Steel was 28.8%.
Tata Steel said its Committee of Directors has approved the allotment fo 1.2 crore shares of Rs 10 each to Tata Sons at a premium of Rs 584 per share.
Tata Steel shares were trading 0.68% higher at Rs 432.25 apiece at the BSE in late afternoon session.