On Friday, the company had announced a voluntary offer to buy up to 17.24 lakh shares in Tata Sponge Iron, an associate firm, at Rs 375 per share, entailing a total outgo of Rs 65.02 crore.
In a separate exchange filing, the steel major had said it will acquire up to 14.65 lakh shares in The Tinplate Company for Rs 60 a share for a total of about Rs 87.92 crore.
At 10.10 a.m., shares in The Tinplate Company traded 16.77 per cent higher at Rs 54.65 on the BSE, while Tata Sponge Iron stocks traded 12.27 per cent higher at Rs 344.15. The Sensex traded 0.77 per cent higher at 17,080.
Following the offer, Tata Steel's stake in Tata Sponge Iron would go up to 51 per cent and up to 73.44 per cent in The Tinplate Company, if subscribed fully.
Tata Sponge Iron has manufacturing facility at Bilaipada in Odisha. It was initially set up as a joint venture company between Tata Steel and the Industrial Promotion and Investment Corporation of Orissa Limited (IPICOL). However, in 1991, Tata Steel bought out IPICOL's stake and made it an associate firm. Tata Sponge Iron's total production capacity now stands at 3.9 lakh tonne a year and 26 MW power generation capacity.
The Tinplate Company is the largest domestic producer of tin coated and tin free steel sheets with about 40 per cent market share.
The details of the offer would be made through a public statement on or before June 22.

