Singapore Airlines says it is in talks to sell its 49% stake in Virgin Atlantic.
News agencies, including Reuters and Bloomberg, reported that Delta Air Lines was the interested party according to unnamed sources.
Billionaire Richard Branson holds a controlling 51% of Virgin.
A partnership with Virgin would allow US-based Delta to access the lucrative transatlantic business travellers market between the US and London.
Singapore Air bought its 49% stake in Virgin in 2000 for about £551m ($884m). Since then Singapore Air has injected further capital into Virgin and now values its total investment at £600.25m.
Singapore Air said in a brief statement that it was "in discussions with interested parties" to possibly divest its shareholding, but did not name the potential buyers.
It added that the talks may or may not lead to a transaction.
Delta, the second-biggest US airline, has been looking to buy into Virgin for more than two years, as it looks to increase its access to London's Heathrow airport.
Virgin is the second-biggest airline at Heathrow airport, where landing slots are hard to acquire.
Virgin has also been looking for investors, hiring Deutsche Bank in 2010 to look into its options.