(Reuters) - Amazon.com Inc on Friday defeated an appeal by the U.S. Internal Revenue Service in what the online retailer has called a $1.5 billion (£1.2 billion) dispute over its tax treatment of transactions with a Luxembourg subsidiary.In a 3-0 decision, the 9th U.S. Circuit Court of Appeals in Seattle upheld a 2017 ruling by the U.S. Tax Court related to intangible assets that Amazon.com transferred in 2005 and 2006 to the unit, Amazon Europe Holding Technologies SCS.Intangible assets..