Moody’s has trimmed the rating for Greece by 2 notches to Ca Monday which is just one notch before the default status. The ratings agency warned that chance of a default is now “virtually 100 percent.”

Moody’s noted that while the bailout agreed last week by euro zone leaders will help Greece to reduce its debt, the country still faces medium-term solvency challenges and significant implementation risks.

"The announced EU program along with the Institute of International Finance's statement implies that the probability of a distressed exchange, and hence a default, on Greek government bonds is virtually 100 percent," the agency said in a statement.

"(Greece's) stock of debt will still be well in excess of 100 percent of GDP for many years and it will still face very significant implementation risks to fiscal and economic reform," it added.

The ratings agency is wary that the euro zone bailout package sets a negative precedent for investors on future restructuring.