NEW YORK--(BUSINESS WIRE)--Fitch Ratings has assigned an initial Issuer Default Rating (IDR) of 'BBB' to American Assets Trust, Inc. and its operating partnership American Assets Trust, L.P. (collectively, AAT, American Assets Trust, or the company). A full list of Fitch's ratings for AAT follows at the end of this release. The Rating Outlook is Stable. KEY RATING DRIVERS The 'BBB' IDR reflects the company's credit strengths, which include a portfolio focus on high barrier-to-entry U.S. west co