EU Commissioner of Competition Margrethe Vestager speaks during an interview to AFP at the European Commission in Brussels on May 3, 2019.

Fiat will have to repay up to 30 million euros back in taxes, Europe's second highest court ruled Tuesday.

In a separate case, the European general court decided that Starbucks did not have to repay a similar amount in taxes.

This comes after the European Commission, the EU's executive arm, said in 2015 that both companies had received illegal tax benefits, provided by Luxembourg and the Netherlands.

Fiat told CNBC via email that it was "disappointed with the General Court's judgment and is considering the next steps to take in this matter."

"The matter is not material to the Group," the spokesperson for Fiat Chrysler Finance Europe, also said.

Starbucks told CNBC via email: "Starbucks welcomes the decision by the European Court that makes clear Starbucks did not receive any special tax treatment from the Netherlands. Starbucks pays all of its taxes wherever they are due."