NEW YORK--(BUSINESS WIRE)--Fitch Ratings has upgraded one and affirmed six classes of notes issued by ACAS CLO 2007-1 Ltd./Corp. (ACAS CLO 2007-1). Fitch has also revised the Outlooks on two classes of notes to Positive. A full list of rating actions follows at the end of this rating action commentary. KEY RATING DRIVERS The upgrade and the Outlook revisions are the result of increased credit enhancement due to the significant amortization of the capital structure and the stable performance of