S&P says there’s a 50% chance Greece will leave the euro by Tom Huddleston, Jr. @FortuneMagazine June 29, 2015, 3:55 PM EDT E-mail Tweet Facebook Linkedin Share icons Standard & Poor’s has once again lowered its outlook for Greece’s economic future as uncertainty mounts over the troubled country’s debt crisis. The ratings agency on Monday downgraded its sovereign rating for Greece to CCC- after previously lowering its rating to CCC earlier this month. That’s a fairly quick downgrade for the S&P, which had previously dropped Greece’s rating in mid-April, from BBB- to CCC+. The latest rating drop comes with the S&P’s assessment that the likelihood of a Greek exit from the euro zone is now around 50%, with the ratings agency predicting that Greece will default on its debt within six months without any unexpected change to the country’s financial health. Greek citizens are due to vote this weekend on a new bailout proposal put forth by the country’s euro zone creditors. A “no” vote on the referendum is expected to pave the way for Greece’s exit from the euro zone. Greek leaders, including Prime Minister Alexis Tsipras, have condemned the proposed agreement, which would send billions of dollars in additional financial aid to the country. Greece’s current bailout expires at the end of June, at which point the country’s first debt repayment of about $1.8 billion will become due to the International Monetary Fund. —Reuters contributed to this report.