NEW YORK--(BUSINESS WIRE)--Fitch Ratings has assigned an 'A+' rating to Northern States Power Company-Minnesota's (NSP-Minnesota) $600 million issuance of first mortgage bonds (FMBs), composed of two $300 million tranches. The 2.20%, 5-year FMBs maturing Aug. 15, 2020 and the 4.00%, 30-year FMBs maturing Aug. 15, 2045 will rank pari passu with NSP-Minnesota's existing secured debt. The expected settlement date for the FMBs is next Tuesday, August 11. The Rating Outlook is Stable. Net proceeds w