...NEW YORK (S&P Global Ratings) Sept. 14, 2016--S&P Global Ratings today said it assigned its '##-' debt rating on Navient Corp.'s (##/Negative/B) $500 million senior unsecured notes due in 2023. The debt rating is one notch below the counterparty credit rating because Navient's tangible unencumbered assets are less than its outstanding unsecured debt. We exclude from unencumbered assets the company's overcollateralization balances associated with its asset-backed securities trusts. Navient's intended uses of proceeds are for general corporate purposes, including debt repurchases. Although our ratings and outlook on Navient are unchanged at this time, we view the demonstrated access to the unsecured debt markets favorably, as well as any debt repurchases with the proceeds. We expect Navient's portfolio of student loans will produce substantial and stable cash flows; however, the majority of its loan portfolio is encumbered by secured borrowings. The negative outlook reflects that Navient's...