...NEW YORK (S&P Global Ratings) March 13, 2019--S&P Global Ratings today assigned its '###' issue-level rating to American Electric Power Co. Inc.'s (AEP) proposed equity units. The equity units consist of a purchase contract that obligates the owners of the units to purchase AEP's common stock as of mid-March 2022, and a remarketable junior subordinated note due 2024. We have assigned high equity credit (100% equity treatment) to the issuance because of the mandatory convertible feature that requires the issuance of common equity within a three-year timeframe. The company intends to use the net proceeds from the equity units to refinance outstanding debt issues. We notch the equity units two notches below our 'A-' issuer credit rating on AEP, which reflects the subordination and deferability on the instruments for the first three years. The rating applies to the company's obligation to service the debt component, as well as its obligation to issue common shares under the forward contract....