FOR the first time this year, Europe's approaching single currency, the euro, looks in danger. Having withstood an economic crisis in Asia and and oil-price collapse, it seemed nothing could stop the euro launch from being anything other than a success. But the sharp deterioration in the Russian economy has posed fresh doubts, even raising the possibility some of the 11 currencies which will merge to create the euro on January 1 could be the target of speculative attacks. Russia is a key importer of European goods and services, and a substantial borrower from European banks. Given that some entrants into European economic and monetary union have not convincingly met the Maastricht criteria, the risk of contagion from a country both geographically and economically close to Europe has sent tremors through foreign exchange markets. Concern over the Italian lire in particular has grown to such a level that Italy's finance minister, Carlo Azeglio Ciampi, last week was compelled to reiterate his belief that the 'state of the Italian economy, like that of all the 11 countries participating in the euro, is solid'. Some economists beg to differ. Recent statistics show Italy is still far from reaching the Maastricht criteria on the levels of public-sector debt and the budget deficit. While this might not block Italy from entry into the euro, economists said it might have a damaging influence on the euro project as a whole. Any concern the euro is not as strong as initially hoped is likely to prompt a flight to quality. That almost certainly would benefit German bunds, creating a wide spread between euro country bonds which are deemed weak - like Italy's - and those seen as stronger. 'The problem with the euro bloc is that capital tends to flow into the deutschemark, because its market is large and liquid, and because . . . if anything happened to EMU, the deutschemark would have the backing of the Bundesbank,' Monument Derivatives economist Stephen Lewis said. Such a scenario would do little to convince the markets that in the few crucial months before the euro is launched there is a pronounced trend towards economic convergence. But some economists see the Russian crisis as having a benign impact on the euro. 'If it sends any signals, it is that there will be rapid interest rate cuts,' said Brian Martin, chief currency economist at Barclays Capital.