...American Transmission Systems, Inc.'s Ratings and Outlook reflect relatively low business risk, strong standalone credit metrics and credit supportive Federal Energy Regulatory Commission (FERC) rate regulation. The ratings also take into consideration Brookfield Super-Core Infrastructure Partners (Brookfield) 49.9% ownership interest in ATSI's corporate parent, FirstEnergy Transmission, LLC (FET) and the rights and protections afforded to Brookfield in its operating agreement with FirstEnergy Corp. (FE). FE owns 50.1% of FET....