"The company based on the review of its portfolio is proposing to sell shares of face value of Rs 2 each of Tata Motors to institutional investors over the stock exchange for a value not exceeding Rs 1,250 crore," Tata Steel said in a BSE filing.
The company said the price for sale to institutional investors will be discovered through a book-building process.
It further said: "The company also proposes to sell shares of face value of Rs 2 each of Tata Motors to Tata Sons around the market price through an off-market transaction for a total value not exceeding Rs 1,250 crore."
Last month, Tata Steel had sold 2.18 per cent of its stake in another Tata group firm Titan to Tata Sons for over Rs 637 crore.
The stock of Tata Steel was trading at Rs 232.70, up 1.09 per cent, on BSE.