CHICAGO--(BUSINESS WIRE)--Fitch Ratings has downgraded the ratings of Arcos Dorados B.V. (AD) and Arcos Dorados Holdings Inc. (Arcos), as well as the BRL675 million and USD475 million senior unsecured notes issued by Arcos, to 'BB+'. The Outlook for the corporate ratings is Negative. A full list of rating actions follows at the end of this press release. KEY RATING DRIVERS The downgrade of Arcos' and AD's ratings reflects the company's weak operating performance, which has felt the impact of a