CHICAGO--(BUSINESS WIRE)--Fitch Ratings has assigned a 'BBB-' rating to Petroleo Brasileiro S.A.'s (Petrobras) proposed senior unsecured century notes issuance. The notes, which mature in 2115, will be issued through its wholly owned subsidiary, Petrobras Global Finance B.V. (PGF), and will be unconditionally and irrevocably guaranteed by Petrobras. Proceeds will be used for general corporate purposes. Fitch currently rates Petrobras 'BBB-'. The Rating Outlook is Negative. KEY RATING DRIVERS Pe