The pledge of international aid for Greece, designed to help the country tackle its debt crisis, has failed to erase the likelihood of a credit downgrade, Moody’s Investors Service said. The Mediterranean nation faces «significant execution risk» in implementing a plan to reduce its budget deficit, Sarah Carlson, Moody’s lead analyst for Greece, told Bloomberg yesterday. «More specificity of the nature of the EU assistance if it were necessary is helpful, if nothing else, for calming the markets,» Carlson said. «The amount of money that a government spends on interest payments relative to the revenues that it takes in is a very important variable that we look at, and one of the things that affects that is the cost of borrowing.» Greek borrowing costs plunged yesterday, with the two-year note yield falling the most on record, after euro-region finance ministers said on Sunday that they would offer as much as 30 billion euros in three-year loans at about 5 percent, compared with a yield of 7.19 percent for its three-year notes at the close of trade last week. As much as 15 billion euros would also come from the International Monetary Fund should Greece ask for it. Moody’s downgraded Greece one step to A2 in December, citing «medium- to long-term solvency risks.» On Monday, ratings agency Fitch said it is concerned that Greece will continue to struggle to rein in its budget deficit even if were to receive European Union support. Fitch added that a rescue plan will not result in any change to the country’s rating.