European Union antitrust regulators will publish details on Friday of their investigation into online retailer Amazon's tax-minimising arrangements with Luxembourg.
The European Commission, which made the announcement on Thursday, opened its investigation in October, making the U.S. company the latest global firm to have its tax practices assessed by the EU.
The investigation focuses on whether Luxembourg broke EU state aid rules by agreeing a deal which allows Amazon to operate almost tax-free in Europe.
The Commission is also investigating whether a unit of Italian carmaker Fiat benefited from unfair state aid to the detriment of competitors as a result of its tax arrangements with the tiny duchy.
It is separately probing deals between Apple and Ireland and Starbucks and the Netherlands.
Luxembourg has faced international criticism following media revelations in November based on leaked documents -- dubbed "LuxLeaks" -- that detailed its role in helping companies channel profits through the country and pay low tax rates rather than higher rates in states where they did more business.
The leaks put pressure on European Commission President Jean-Claude Juncker, former long-time prime minister of Luxembourg, to explain his role in the country's tax policies.
Juncker has defended the country's tax practices, but is now promoting a plan for a common EU system to share tax information.
