NEW YORK (S&P Global Ratings) April 17, 2019--S&P Global Ratings today assigned its 'A+' issue-level rating to New York City-based pharmaceutical company Bristol-Myers Squibb Co.'s proposed senior unsecured notes and placed them on CreditWatch with negative implications. Bristol-Myers is seeking to exchange the proposed notes for $19.85 billion of outstanding public debt at Celgene Corp., mirroring the Celgene notes in terms of principal amount, interest rate, and maturity date. The proposed notes are contingent on Bristol-Myers successfully closing its acquisition of Celgene. The exchange is offered to all of Celgene's outstanding debt except for Celgene's $500 million of senior notes due 2019, which mature in May 2019. Following the close of the acquisition of Celgene, expected in the third quarter