NEW YORK--(BUSINESS WIRE)--Fitch Ratings has assigned a 'BB/RR1' rating to Tenet Healthcare Corporation's (Tenet) $900 million senior secured notes due 2020 and a 'B-/RR5' rating to Tenet's $1.9 billion senior unsecured notes due 2023. Proceeds will be used to fund the planned acquisitions of a 50.1% ownership interest in United Surgical Partners International (USPI), and the purchase of Aspen Healthcare, as well as to refinance certain of Tenet's and USPI's outstanding debt. KEY RATING DRIVERS