The summit to herald a new era of European unity with the launch of a single currency regressed into a daylong squabble before leaders agreed early today on who will head the bank that controls the euro.

European leaders finally selected Dutchman Wim Duisenberg as chief of the new European Central Bank, but with the proviso that he leave in 2002, when Frenchman Jean-Claude Trichet would take over.British Prime Minister Tony Blair, the chairman of the summit, made the announcement at an early morning news conference after an 11-hour row between European leaders.

The dispute over the central bank post marred celebrations at the landmark meeting of European Union leaders called to confirm the selection of 11 nations that will adopt the euro as their shared currency on Jan. 1 and create an unprecedented economic union.

France and Germany are Europe's strongest economies and their drive for unity is the engine behind the single currency plan, but they became locked in a bitter fight to nominate the first president of the bank.

Germany led the other countries in opposing French demands that Trichet, the French central bank governor, get the job, then fought a compromise deal where Trichet would split the eight-year term with Duisenberg.

Chancellor Helmut Kohl feared a deal to divide the term would cast doubt on the European bank's freedom from political interference. Kohl, who faces elections in September, is under pressure at home to guarantee the euro will be as strong as the mark and the ECB as impartial as Germany's Bund-es-bank.

French President Jacques Chirac wanted a Frenchman in charge of the ECB to counter the Germanic image of the bank, which will be based in the gleaming 30-story "Eurotower" in the heart of Germany's financial capital of Frankfurt.

"It is an historic day because the euro is going to have a huge impact on the future economy of Europe and therefore the future of the people of Europe," Blair said before the summit.

"It's going to have an impact on countries in the euro, those outside it and the rest of the world," he told BBC radio.

The euro's launch will create a vast economic bloc stretching from Finland's Russian border to the Atlantic shores of Ireland to the tip of the Italian boot. Almost 300 million people will have euros in their pockets and purses after the new banknotes and coins arrive in 2002.

Euroland, as people here are already calling the new bloc, will be the world's biggest trading power, accounting for 18.6 percent of global commerce. It will represent almost a fifth of world economic output, about the same proportion as the United States.

"A page has turned, and a new chapter opens in our history," said Italian Prime Minister Romano Prodi.

Germany and France will be at the heart of the currency union. With them will be Italy, Spain, the Netherlands, Austria, Belgium, Portugal, Ireland and Luxembourg.

Of the other European Union nations, Britain, Sweden and Denmark have decided to stay out to retain national control of monetary policy. Greece failed to make the economic requirements for membership, but hopes to join in 2001.