NEW YORK--(BUSINESS WIRE)--Fitch Ratings has assigned an 'A' rating to PECO Energy Co.'s (PECO) new $350 million issue of 10-year first-mortgage and refunding-mortgage bonds. Proceeds will be used for general corporate purposes. The Rating Outlook is Stable. KEY RATING DRIVERS Strong Credit Profile: Fitch expects PECO's credit measures to remain strong relative to both Fitch's target ratios for the current rating level and the company's' peer group of 'BBB+' rated distribution utilities. Over t