International ratings agency Standard & Poor's said it had put six leading eurozone economies with the highest AAA rating, including Germany and France, on the list for possible downgrade.
A total of 15 out of 17 eurozone economies were put on the "creditwatch" list, which means that there is 50 percent possibility that their ratings will be downgraded within 90 days. S&P also said it maintained the negative outlook for Cyprus, and Greece was out of the list.
"Systemic stresses in the eurozone have risen in recent weeks to the extent that they now put downward pressure on the credit standing of the eurozone as a whole," S&P said on its website.
"We now assign a 40% probability of a fall in output for the eurozone as a whole," the statement reads.
The rating of six eurozone economies with the highest AAA rating - Austria, Finland, France, Germany, Luxembourg and The Netherlands - may be downgraded by one notch and by up to two notches for the other governments.
The eurozone sovereign ratings may be reviewed "as soon as possible" in the wake of the EU summit to take place on December 8-9.
