...+ U.S.-based miner Cliffs Natural Resources Inc.'s credit measures deteriorated sharply in 2014 due to low iron ore prices and high costs in Eastern Canada. + We lowered our iron ore price assumptions through 2016, which pushes our leverage estimate above 6x adjusted debt to EBITDA for next year. + We are lowering our corporate credit and senior unsecured note ratings on Cliffs to '##-' from '###-'. At the same time, we are assigning our '##+' issue-level rating to the company's senior unsecured revolving credit facility, with a '1' recovery rating. + The negative outlook reflects the possibility of another downgrade if Cliffs sustains weaker credit measures, particularly if it is unable to obtain additional flexibility under its financial covenants in early 2015. NEW YORK (Standard & Poor's) Oct. 7, 2014--Standard & Poor's Ratings Services said today it lowered its corporate credit rating on Cliffs Natural Resources Inc. to '##-' from '###-'. At the same time, we lowered our issue-level...