The EU has slammed Ireland for giving special tax rebates for Apple, which may constitute illegal state aid. In a letter published Tuesday, the European Commission alleged “Irish authorities confer an advantage on Apple” through its tax treatment. Tax deals with Apple between 1991 and 2007 have “several inconsistencies,” according to the letter, and may violate international standards. The letter from the 28-nation bloc warns Ireland that its tax relationship with Apple raises “doubts about the compatibility” with EU law. The EU first announced its Apple investigation in June. It is seeking several other documents from Ireland, and it could be several months before the EU makes a final decision.