United Parcel Service Inc (UPS.N), the world’s largest package delivery company, is seeking 1.742 billion euros in damages from EU antitrust regulators after they blocked its bid to buy Dutch peer TNT five years ago.

The move was expected after an EU court agreed with UPS in March 2017 that the European Commission had been wrong to prevent the deal.

The Commission’s 2013 decision “is tainted with serious breaches of rules of law”, UPS said in a filing with the Luxembourg-based General Court, Europe’s second-highest.

“The applicant claims these breaches in turn caused the applicant’s loss because had they not taken place, UPS would have acquired TNT,” the European Union’s official journal said on Monday in summarizing the complaint.

The Commission will defend itself in court, a Commission spokesman said.

Merger vetoes are rare. Of 6,833 potential mergers notified to the Commission since 1990, only 27 have been rejected.

The European Commission rejected the proposed 5.2 billion euro deal in 2013, saying UPS had not offered sufficient concessions to allay concerns that the deal would hurt consumers. UPS challenged this decision.

The General Court of the European Union, the EU’s second highest court, found that the Commission had infringed UPS’s rights of defense by relying on a different econometric model in its analysis than that used in previous exchanges of views and arguments.

The Commission has appealed against that court ruling.

U.S. rival FedEx (FDX.N) acquired TNT in 2015, winning unconditional EU regulatory approval.