Cardiff Airport should be kept in public ownership in the long term, according to the CEO of Qatar Airways.
His Excellency Akbar Al Baker warned the Welsh Government that selling the airport could make it vulnerable to hedge funds.
The Welsh Government has previously said that it does not expect to own the airport indefinitely.
The Cardiff Airport chairman Roger Lewis claimed last month the public's investment could be recouped by 2021.
Mr Al Baker was speaking at the Cardiff launch of the service between Doha and Cardiff Airport.
At the launch, First Minister Carwyn Jones said: "I have said many times that I don't see the future as necessarily being one where the Welsh Government owns the airport 100%."
"We will look for a private partner at the right time, we probably want to keep a controlling interest in the airport."
But Mr Al Baker warned against selling off too much.
He said "It is important that you don't rush into privatising or giving out the shareholding of the airport to private entities because what would happen is that hedge funds would get involved and they will start charging the airlines an arm and a leg and make the airport unattractive to the airlines."
Mr Al Baker also said the company was interested in investing in a five-star hotel in Cardiff, although it is understood this is at a very early stage and no site has been reviewed.
Mr Jones agreed to work with him to "move this project forward".
Doha is an international hub and flights from Cardiff can connect to flights to many international destinations.
The airline will run flights five days a week until June and after that will fly every day.
The Welsh Government has also signed a marketing partnership with Qatar Airways to promote Wales around the world.