U.S.-based iron ore producer Cliffs Natural Resources Inc. has completed a debt exchange offer in which $512 million in debt principal consisting of second-lien notes and various senior unsecured notes was exchanged for $219 million in new 8.00% 1.5-lien senior secured notes due 2020. We are raising the corporate credit rating to 'CCC+' from 'SD'. This indicates the completion of the exchange, but underscores that we continue to view Cliffs' capital structure as unsustainable at this time. We are assigning our 'B' issue-level rating to the new 1.5-lien notes. The recovery rating is '1'. We are lowering our issue-rating on the first-lien notes to 'B' from 'BB-', reflecting the new corporate credit rating. The recovery rating on the notes remains