Published by Mark Smith-HalvorsenThe euro rose against the yen but struggled against other major competitors this morning (April 7th) after the yields on Greek sovereign bonds rocketed yesterday, raising concerns about the country's capacity to pay off its debts.A sudden selloff in trading yesterday pushed bond yields to 7.1 per cent, which in turn pushed up the country's cost of borrowing to record levels and sparked scepticism about its ability to pay off its debts.Speaking to the Times, Brian Coulton, a director of Fitch Ratings, said that while the yields will cause problems for the country, the greatest concern at present will be the acute volatility that precipitated the selloff."Greece needs to access capital markets to refinance maturing debt. It is harder to issue bonds when the market is volatile; investors get nervous," he said.The selloff came amid speculation that Greece's finance minister George Papaconstantinou was attempting to renegotiate the terms of a rescue deal agreed by EU leaders last month.For more information on foreign exchange treasury services and risk management, visit our Corporate FX site