We are assigning our 'BB-' corporate credit rating to U.S. midstream energy master limited partnership Tesoro Logistics L.P. (TLLP). We are also assigning our 'BB-' senior unsecured rating to the partnership's proposed $310 million senior unsecured notes, which are being co-issued by Tesoro Logistics Finance Corp. Our ratings on TLLP reflect its modest scale and aggressive financial leverage, but also its revenue stability and close business ties with its sponsor, Tesoro Corp. (BB+/Stable/--). The outlook is stable and reflects our expectations that TLLP will maintain a mostly fee-based business, while managing its leverage in the 4x area or lower as it pursues growth opportunities. On Sept. 4, 2012, Standard&Poor's Ratings Services assigned its 'BB-' issuer credit rating to
