OREANDA-NEWS. A.M. Best has downgraded the financial strength rating to A- (Excellent) from A (Excellent) and the issuer credit rating to “a-” from “a+” for American Capital Assurance Corp (ACAC) (St. Petersburg, FL). These rating actions follow the recent transaction between ARX Holding Corp (ARX) and Ark Royal Holding, LLC (Ark Royal), resulting in the transfer of ownership of ACAC from ARX to Ark Royal. The outlook for each rating is stable.