Amazon. com's tax affairs will be back in the limelight as the European Union publishes details of its investigation into a sweetheart deal with Luxembourg. The European Commission will release a non-confidential version of a letter outlining suspicions that the online retailer unfairly shifted profits to lower its taxes, the regulator said.

The letter was sent to Luxembourg officials as the EU opened a formal investigation into the Amazon tax accord on October 7th. Most European profits of Amazon were recorded in Luxembourg but were not taxed there as a result of a 2003 tax ruling, which was still in force today and applied to a subsidiary in the country, the EU said at the time.

The commission's inquiry into tax deals was expanded last month as the competition regulator asked all EU countries to give it information about financial agreements with multinational corporations. Until then, the EU had focused on specific companies with investigations into Irish tax deals with Apple, Luxembourg's taxation of Fiat Finance and Trade and Amazon, as well as the Netherlands' treatment of Starbucks.

Drew Herdener, a spokesman for Amazon, declined to immediately comment. – (Bloomberg)