The launch of Europe's new single currency was almost universally greeted as a triumph Thursday, despite the inevitable confusion and lines in shops and the discovery of the first forged euro notes.

"This success proves the euro is really going to change Europe," Portuguese Central Bank Governor Vitor Constancio told reporters in Frankfurt. European Central Bank President Wim Duisenberg was due to give his first assessment at a news conference at 1330 GMT.

On financial markets, the euro held on to most of the gains it notched up against other major currencies on Wednesday in what traders said was a rally driven by relief that the launch had been largely trouble-free.

"It's official — the euro is an overwhelming hit," the normally restrained Wall Street Journal Europe said in a front page headline.

Forged Notes

Meanwhile in Germany, police said a 12-year-old girl had found a forged 50 euro note on a train, the first counterfeit case to come to light since the new cash was issued to more than 300 million Europeans on New Year's Day.

Police said the girl spotted the note on a train on Wednesday. "She noticed it was a forgery because it did not have any of the security features,'' said a spokesman for the police in Siegburg, western Germany. 

"Apparently it was not very good, but it was printed on both sides which is better than some forgeries you get.'' 

"She was pleased at first but realized it was counterfeit,'' the spokesman said. The police spokesman said the girl would not be getting a reward.

Forgery is only one of the number of crimes expected to hit euro users in the coming days. 

On Wednesday, a gunman stole $68,400 worth of euros from a post office savings branch in Greece and thieves hit a rural bank and an ATM machine in Ireland.

Brandishing a pistol, a man forced a cashier at the savings branch in the northern Athens suburb of Holargos to fill two bags with euro notes before fleeing on foot, police said. He also stole a small amount of drachmas, which are still legal tender until the end of February. No one was injured.

In Ireland, three assailants, two of them armed with a hammer and a knife, threatened staff at a branch of Allied Irish Banks before grabbing about 2,000 euros, worth $1,800, from a till and escaping in a waiting car.

Already on Monday, a German bank robber seized tens of thousands of euros hours before the midnight launch of the single currency. The cash, stored in a savings bank in the northern German town of Pinneberg, was sealed in plastic and had just been delivered by the regional central bank for public distribution.

Tensions in Italy

Strains emerged in Italy's government over the birth of the euro but problems elsewhere were scarce on Thursday as EU central bankers met to applaud themselves on the currency's largely trouble-free launch.

Italian Foreign Minister Renato Ruggiero attacked cabinet colleagues in a newspaper interview for belittling the vast project -- Europe's biggest logistical operation in peacetime — to replace 12 national currencies with euro notes and coins.

"The differences of opinion aren't marked, they are very marked," he told Corriere della Sera in comments which underscored faultlines in the centre-right administration.

The European Commission in Brussels said there was no evidence that the changeover was causing any general increase in prices — contrary to the view of an Italian consumer group that said Italians were being "massacred" by rises for everything from espresso and pizza to tickets for museums.

Now that goods are being priced and paid for in a single currency throughout 12 countries, citizens can see much more easily how wildly prices vary.

Reporters found a can of Coca-Cola costs more than three times as much in Finland (1.18 euros) as in Spain (0.33), while a McDonald's Big Mac costs about twice as much in Helsinki (4.50) as in Athens (2.11).

No Major Disruptions

On Wednesday, the first working day after the New Year holiday, there were hitches but no major disruption. All 2,600 of Austria's cash machines crashed for about an hour, and Italian travel agents could not issue train tickets due to software problems.

Shops, railway stations and motorway toll booths all saw longer lines than usual, but strikes at Italy's central bank and at commercial banks in France had little or no apparent impact.

The euro was launched in "virtual" form three years ago as an accounting unit and a traded currency on financial markets, where its value has fallen from around $1.17 to around 90 U.S. cents now.

But Europeans had to wait until Tuesday to get their hands on euro banknotes for the first time, the culmination of a vast project aimed at integrating European economies and stimulating investment, travel and trade.

Reuters and the Associated Press contributed to this report.