S&P Global Ratings downgraded Concordia International Corp.'s corporate credit rating to selective default from CCC-.

The rating agency removed the specialty pharmaceutical company's rating from CreditWatch, where it was earlier placed with negative implications.

The downgrade comes after Concordia failed to make the Oct. 16 interest payment on its $735 million senior unsecured notes due 2023.

S&P sees Concordia's debt level as unsustainable, adding it does not expect the company to make a payment within the the 30-day grace period.

The agency believes the ongoing negotiations with debt holders will likely result in a distressed exchange, corporate restructuring, or bankruptcy.

S&P Global Ratings and S&P Global Market Intelligence are owned by S&P Global Inc.