Monarch Airlines is considering both inbound and outbound bids less than two years after it nearly collapsed.
Monarch Group has confirmed it has "generated inbound interest". And it has taken on Deutsche Bank to "evaluate both inbound and outbound opportunities".
Easyjet is said to be considering a bid for the airline along with China's HNA.
And Monarch itself has been linked with approaches for several European rivals.
A Monarch spokesman said: "The continued success of the Monarch Group has generated inbound interest and Deutsche Bank is continuing to work with us to evaluate both inbound and outbound opportunities.
"The key focus of management and our shareholders, Greybull, remains the successful development and growth of Monarch."
The Sunday Times first reported that Easyjet is considering an approach in competition with China's HNA. Like Easyjet, Monarch's base is Luton airport.
The Sunday Telegraph, meanwhile, reported Monarch is weighing up bids for Air Berlin, TuiFly and Thomas Cook Airlines.
Monarch was close to going under in October 2014 before Greybull Capital acquired the airline from the Mantegazza family, who had owned it since the 1960s.
Run by brothers Marc and Nathaniel Meyohas, Greybull pumped £125m of funding into the airline to keep it flying.
Earlier this month, Greybull acquired Tata's Scunthorpe steel plant for a nominal £1.
Easyjet declined to comment. HNA has been asked for comment.