U.S. midstream energy partnership Tesoro Logistics L.P. has grown its asset base while maintaining stable, fee-based cash flow and acceptable credit measures. We are raising our corporate credit rating to 'BB' from 'BB-'. We are also raising our issue rating on the partnership's senior unsecured notes to 'BB' from 'BB-' and maintaining the '4' recovery rating. The outlook is stable. The partnership's creditworthiness benefits from its strategic importance and close business ties with Tesoro Corp., which controls the general partnership and is a very significant customer. The stable outlook reflects our expectation that Tesoro Logistics' cash flow will remain fee-based while it manages its financial leverage at 4x or less as it pursues growth opportunities. On Sept. 10, 2014, Standard
