The investment could be more than $100 million but discussions are at an early stage and the size of the stake and the investment are not clear yet, the sources said.

TPG declined to comment. Jet Airways did not respond to an email seeking comment.

Jet Airways told staff earlier this month it was running out of money, a source had told Reuters, but it has denied this and said it is confident of cutting costs and keeping its planes flying.

Days later, Jet Airways deferred reporting earnings and the airline's shares fell to a three-year low, with analysts saying the company urgently needed to recapitalise.

TPG is looking to buy a stake in Jet Airways' frequent-flyer loyalty programme and has appointed Morgan Stanley to advise on the potential deal, the Mint newspaper reported earlier on Monday, citing sources.

The deal with TPG could value the loyalty programme, Jet Privilege Private Ltd, at $400 million, the newspaper said, adding that Jet continues to engage with Blackstone Group for a similar deal.

Blackstone and Morgan Stanley were not available outside business hours.

The airline, which is partly owned by Etihad Airways, had net debt of 81.5 billion rupees ($1.16 billion) as of end-March. The carrier has said it is meeting all its payments obligations to lenders and is also looking at ways to cut costs to create "a healthier and more resilient business".

($1 = 70.0900 Indian rupees)

(Reporting by Sumeet Chatterjee in Hong Kong, Aditi Shah in New Delhi, Tanvi Mehta in Bengaluru; Editing by Sunil Nair and Manolo Serapio Jr.)