The European Union ordered Starbucks and Fiat on Wednesday to each repay up to 30 million euros in back taxes in a landmark tax avoidance case pursued in the wake of the Lux Leaks scandal.

"Luxembourg is to recover 20-30 million euros ($23-34 million) from Fiat and The Netherlands to recover 20-30 million from Starbucks Manufacturing -- unpaid taxes due to illegal state aid," EU Competition Commissioner Margrethe Vestager said in a tweet announcing the decision.