LONDON, April 16 (Reuters) - Fitch's sovereign ratings in eastern Europe do not factor in any expectation the European Union will allow fast-track euro adoption, but a change in that policy would likely lead to upgrades, Fitch said on Thursday.
The economic crisis has caused policymakers in some countries in the EU's eastern wing to speed up their efforts to join the single currency, seeing it as a potential shield against turmoil.
In the face of extreme currency volatility, Poland and Hungary lobbied for leeway on adopting the euro earlier this year but both the bloc's executive Commission and the European Central Bank say strict euro requirements can not be relaxed.
"Fitch does not expect a relaxation of EU policy on joining the euro area," Fitch said in a statement.
Before joining the euro zone, countries must keep currencies pegged to the euro in the ERM-2 antechamber where it has to stay in a plus/minus 15 percent band around a central parity.
Analysts say that could pose problems since investors began ditching assets across central and Eastern Europe last year, forcing the Polish zloty and other currencies down double digit percentages against the euro.
Poland's government had said earlier this year it wanted to join the ERM2 in the first half of the year and to swap its zlotys for euros in 2012. It has since backed away from that target.
Fitch said it expected EU authorities to remain resistant to "premature" euro adoption for fear that a country might find itself unable to bear the costs of adjustment.
That, Fitch said, could potentially cause a country to leave the euro "triggering contagion to other countries within the single currency".
Edward Parker, head of emerging Europe sovereigns at Fitch, said: "If there were an unexpected relaxation of EU policy that opened the way for early euro adoption, then Fitch would expect to respond by taking some positive rating actions on the countries concerned."
Overall, Fitch said euro adoption would be positive for the region because it would eliminate the risks of potential balance of payments and currency crises.
"The agency's long-standing position is that euro adoption can lead to one- or two-notch upgrades of foreign currency Issuer Default ratings," Fitch said.
Euro candidates must also meet criteria on long-term interest rates, inflation, foreign debt and budget deficits.
The latter two could pose problems for some countries, because the economic crisis has caused budget revenues to fall and public borrowing to rise.
Fitch said it forecast the next countries to enter the single currency zone would be Estonia, Lithuania and Poland in 2014; the Czech Republic, Hungary and Latvia in 2014 and Bulgaria and Romania a year later.
"Timetables for all countries are uncertain, and both later and early dates are possible," Fitch said.
According to a Reuters poll of analysts taken in January, no country will adopt the euro before 2013. (Reporting by Carolyn Cohn; Writing by Michael Winfrey; Editing by Andy Bruce)