New Delhi: Tata Power Monday said its Board has approved plan to raise up to Rs 5,500 crore through issuance of non-convertible debentures (NCDs) on a private placement basis."The board has approved issuance in one or more tranches, of non-cumulative, redeemable, taxable, listed, rated securities in the form of non-convertible debentures up to an aggregate amount not exceeding Rs 5,500 crore on private placement basis," Tata Power said in a BSE filing.Shares of Tata Power settled 12.40 per cent higher at Rs 77.50 apiece on BSE.