NEW YORK--(BUSINESS WIRE)--Fitch Ratings has assigned a 'BBB' rating to Thermo Fisher Scientific Inc.'s (Thermo Fisher) EUR500 million senior notes. The proceeds of the Euro denominated issue will be used for general corporate purposes, including the repayment of upcoming debt maturities. The Rating Outlook is Stable. The ratings apply to $14.7 billion of debt at March 28, 2015. A full list of ratings follows at the end of this press release. KEY RATING DRIVERS --Thermo Fisher has demonstrated