In a parallel inquiry, the commission said on Wednesday that Luxembourg struck an illegal tax deal with a unit of the auto giant Fiat Chrysler, and ordered the government to collect up to €30 million in unpaid tax to level the playing field. Fiat said its financing unit had not received any state aid from Luxembourg.

European authorities are also investigating Luxembourg’s low-tax arrangement with Amazon, and Apple’s business in Ireland.

Starbucks said it would appeal the commission’s ruling. In a statement, it said it complied “with all relevant tax rules, laws” and international tax guidelines, and paid $3 billion in global taxes between 2008 and 2014. The company said it shared concerns by the Dutch government “that there are significant errors in the decision.”

Tax avoidance is a sore point in the United States, where the largest companies, including Apple, Amazon and many others, routinely try to minimize their bills. In Europe, the cases have hit a raw nerve in countries where citizens have been squeezed by years of austerity, and stoked friction among member states that are jockeying with one another for jobs and investment.

Whether the crackdown will work remains to be seen. “Nothing prevents these companies from continuing to try to optimize their tax operations and their tax liability,” said Nicolas Petit, a professor at the University of Liège in Belgium who specializes in antitrust law. “It also won’t necessarily prevent European countries from saying they’ll just change their tax regimes” to a different format to lure business, he added.

To further dissuade countries from doing tax deals, the commission has proposed that they disclose more tax information. If approved, new rules would require all 28 European Union countries, starting next year, to share basic data each quarter on the sweeteners they are offering to multinationals.