The Hungarian national airline Malev has folded after its financial situation became unsustainable.
"At 0500 GMT... after 66 years of almost continuous operation Malev will no longer take off," it said.
It came after the European Commission ordered Malev to repay various forms of state aid received from 2007 to 2010.
The sums involved amounted to 38 billion forints (130m euros; $171m; £108m), a sum equal to its entire 2010 revenue.
"Despite its best interests the owner can no longer provide financial resources for the operation of the airline in the wake of the condemning decision of the European Commission," an airline statement said.
The European Consumer Organisation, which "defends the interests of all Europe's consumers", said the news came after Spanair's collapse in the very same week.
"This development is yet more incontrovertible proof that the current update of European legislation on air travel must incorporate a mandatory guarantee against airline bankruptcies," it said.
Prime Minister Viktor Orban said on state radio that two Malev planes were still overseas, one in Tel Aviv, the other in the Irish Republic.
The premier said those planes were not allowed to take off because of Malev's debts.