...+ S&P Global Ratings is revising its operating assumptions for U.S.-based integrated oil company Exxon Mobil Corp. We now forecast slower debt reduction than previously expected resulting in credit measures remaining weak for the rating over the next two years. + Consequently, we are revising the outlook on ExxonMobil to negative from stable. + We are affirming our '##+' long-term corporate credit rating on the company, and our '##+' issue-level ratings on its unsecured debt. We are also affirming our 'A-1+' short-term corporate credit and commercial paper ratings. + The negative outlook reflects the potential for a downgrade if we no longer expect cash flow-based credit measures to improve to levels more appropriate for the current rating over the next two years. NEW YORK (S&P Global Ratings) May 24, 2017--S&P Global Ratings today affirmed its '##+' long-term corporate credit and unsecured debt ratings on U.S.-based integrated oil and gas company Exxon Mobil Corp. (ExxonMobil), and revised...