A person familiar with the negotiations to slash Greece's massive debt said private creditors participating in the deal would face an overall loss on their bondholdings of around 70 percent.
Athens and representatives of banks and other investment funds holding Greek government bonds over the weekend came close to a final deal designed to make Greece's debt sustainable.
That is a precondition for further bailout money for Greece from the eurozone and the International Monetary Fund .
The person said Monday that the 70 percent loss was produced by cutting the bonds' face value in half, reducing the average interest rate to less than 4 percent and pushing repayment of the bonds decades into the future.
The person spoke on condition of anonymity because the talks are confidential.