The convertible debenture and or warrants could be converted to as many as 5.22 crore equity shares, SpiceJet said in a regulatory filing.
These shares would be worth nearly Rs 200 crore at today's closing price of Rs 37.40 per piece on the BSE, although the conversion price has not been disclosed.
SpiceJet's board, at their meeting today, approved issuance of "convertible debenture and/or warrants convertible into up to a maximum of 52.177 million equity shares to the promoter of the company on preferential basis...," the filing said.
Sun Group, that promotes SpiceJet, earlier in the day had said it needs capital for expansion and would explore options including equity contribution from existing shareholders and raising debt.
The group has, however, denied any plans for promoters' stake sale in SpiceJet, saying it could consider various other options to raise capital to finance fleet expansion plans.
"We certainly need funds for fleet expansion and whenever there is an attractive opportunity (for partial stake sale), we will definitely look at it, but there is nothing on cards as of now," Sun Group CFO S L Narayanan told PTI.
Asked about the available financing options, Narayanan said it can look at debt, lease finance and funding from existing shareholders, among others.
Sun Group chief Kalanithi Maran and his wife Kavery Maran have resigned from one of the promoter entities of SpiceJet, triggering speculations about a possible sale of Maran family's majority stake in the air carrier.
Shares of the airliner soared 7 per cent to close at Rs 37.40 on the BSE.
SpiceJet operates over 300 daily flights to 38 Indian cities and 4 international destinations through a fleet of 36 Boeing and 12 Bombardier planes.