LONDON, March 27 (Reuters) - The finance ministers of Britain and Germany said on Thursday reform of the European Union needs to guarantee fairness for its countries that do not use the euro currency.
In a jointly authored editorial in the Financial Times, Britain's George Osborne and Germany's Wolfgang Schaeuble said it was important that EU countries outside the euro zone - like Britain - are not disadvantaged by deeper integration of the currency union.
"Future EU reform and treaty change must include reform of the governance framework to put euro area integration on a sound legal basis, and guarantee fairness for those EU countries inside the single market but outside the single currency," they said.
Germany's support for Osborne comes as his Conservative Party tries to placate its eurosceptic factions and voters defecting to the anti-EU UK Independence Party.
British Prime Minister David Cameron has promised to negotiate sweeping reforms to the EU and, if re-elected next year, to hold a referendum by 2017 on whether Britain should stay in it.
Britain joined the EU in 1973, but like Denmark and Sweden, it kept its national currency and monetary policy when the euro launched in 1999. (Reporting by Andy Bruce; Editing by Eric Walsh)