Shares of IndiGo owner InterGlobe Aviation Ltd slumped as much as 5.6 per cent after falling 2.2 per cent on Thursday.

India's biggest airline has expressed interest in buying a stake in Air India after the government gave “in-principle" approval to privatise the debt-laden state-owned carrier.

Analysts have cited concerns about such an investment, given Air India has Rs 52,000-crore ($8.04 billion) debt as per government data.

“The singular concern for any suitor of Air India is its over-leveraged balance sheet,” ICICI Securities says in a note.

Up to Thursday's close, InterGlobe had risen 50.5 per cent this year.