Credit rating agency DBRS started covering Greece with an initial rating of CCC (high) and negative outlook, it said on Friday.
DBRS has an important role in the euro zone, where the European Central Bank looks at four agencies - Standard and Poor's, Moody's, Fitch, and DBRS - when deciding on its haircuts, and takes the highest rating of the four.
"DBRS has today assigned long-term foreign and local currency issuer ratings for Greece at CCC (High) with a negative trend," the rating agency said in a statement.
"Greece's ratings are underpinned by the unprecedented amount of financial support the country received from its euro area partners which has had a highly beneficial effect on its cost of funding, the maturity structure of its debt and on roll-over risk."
DBRS ratings keep Italy, Spain and Ireland from having larger haircuts, or discounts, applied to their sovereign debt, making them more attractive to investors.
Standard & Poor's rates Greece B-, Moody's C and Fitch B-.
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