EASTERN EUROPEAN airlines are sick. Fuel is dear, their markets are small and budget airlines are poaching their passengers. Most eastern European airlines lose money. Malev, Hungary's flag carrier, went bankrupt in February. To avoid a similar fate, four Balkan airlines are considering a novel strategy: flying together.

The idea is not officially on the agenda when the bosses of Croatia Airlines, Montenegro Airlines, Serbia's Jat and Slovenia's Adria meet in Montenegro on May 19th. But it will be discussed behind closed doors. All are in debt and losing money, but between them they have many profitable routes. Serving the scattered Balkan diasporas ought to be lucrative.

Zoran Djurisic, the boss of Montenegro, says that before Yugoslavia collapsed, it represented a market of 10m passengers a year, of which 7m flew with JAT or Adria. Now, 11m people fly to or from the seven ex-Yugoslav states each year, but only 4m use the four carriers meeting in Montenegro. Bosnia's B&H airlines has only one functioning plane. Kosovo, with a large diaspora, has no domestic airline. And Macedonia's MAT went bust in 2010.

Mr Djurisic, who called the summit, says that in the short run the four airlines must co-operate to cut costs. He hopes that, in five to eight years, they might create “a single airline for this whole area, including Bosnia, Macedonia and Kosovo”. Vladimir Ognjenovic, the boss of Jat, says that such a merger is “not realistic” unless all are bought by another foreign airline.

All four have problems. Jat's ageing fleet glugs fuel and needs lots of costly maintenance. Two recent attempts to find a buyer for it failed. Montenegro and Croatia Airlines are packed during the summer holidays but struggle to fill seats during the rest of the year. Adria was bailed out in September with €50m ($69m) from the Slovene government. Now it is looking for a buyer. If that fails, its “last chance” is to join forces with the other three, says Klemen Bostjancic, its boss. A spokesman says Croatia Airlines is not interested in “any type of merger” with the other ex-Yugoslav airlines. But Croatia's minister of transport says that unless the airline revives, a merger with Adria is possible.

Luka Popovic, an analyst, predicts that the “burden of history” will thwart any merger. But the airlines may feel they have no choice. And there is a precedent for a merger in stages: Scandinavian Airlines began as a co-operative venture between the airlines of Norway, Denmark and Sweden in 1946 and then merged in 1951. That could happen in the Balkans, too.