AUSTIN, Texas--(BUSINESS WIRE)--Fitch Ratings has assigned an 'AAA' rating to the following Port of Houston Authority, Texas (the authority) unlimited tax (ULT) bonds: --$62.9 million ULT refunding bonds, series 2015A (tax exempt non-AMT); --$26 million ULT refunding bonds, series 2015B (AMT); --$49.8 million ULT refunding bonds, series 2015C (taxable). The bonds are scheduled to sell via negotiation during the week of July 20. The par values are preliminary and subject to change. Proceeds will