NEW YORK (S&P Global Ratings) Sept. 21, 2017--S&P Global Ratings today assigned its 'AA-' issue-level rating to 3M Co.'s proposed medium-term notes, which the company will issue with 5-year, 10-year, and 30-year maturities. 3M plans to issue an aggregate amount of up to $2 billion of these notes. The company will use the proceeds from the notes to fund the tender of its 6.375% debentures due 2028 and 5.7% medium-term notes due 2037 and for general corporate purposes, which could include funding 3M's previously announced acquisition of Scott Safety from Johnson Controls International PLC. All of our other ratings on 3M remain unchanged. 3M has a broad and diversified portfolio of well-known brand names, good geographic diversification, and solid profitability