It is a co-operative venture, in which states accept a measure of mutual interference in specific areas.

ECONOMIST: What is Europe?

An alternative to all-out mergers, suggested by Jean Dermine, a professor at Insead, a business school near Paris, is to form a co-operative venture with foreign banks.

ECONOMIST: Banks better buck up

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.

ECONOMIST: Four airlines may have to merge