...S&P Global Ratings lowered its long-term rating to '##' from '##+' on Nashville & Davidson County Metropolitan Government, Tenn.'s electric system revenue debt, issued for Nashville Electric Service (NES). The outlook is stable. The downgrade reflects the application of our "U.S. Municipal Retail Electric And Gas Utilities: Methodology And Assumptions" criteria (published Sept. 27, 2018, on RatingsDirect). While we consider the system's fixed-charge coverage metrics to be strong, under our revised criteria we believe these metrics no longer support the prior rating. Despite the recent improvement in fixed-charge coverage for fiscal 2018, we do not anticipate coverage improving further to support a higher rating due to the system's additional debt needs. The electric system had $642 million in total revenue debt outstanding as of June 30, 2018. The electric system's first-lien net revenue pledge secures the bonds. The rating further reflects our opinion of the system's extremely strong enterprise...