Italy’s antitrust agency slapped Volkswagen with a $5.5 million ($5 million euro) fine over the German automaker’s massive diesel engine-fixing scandal.

The antitrust watchdog said the fine related to the marketing in Italy since 2009 of vehicles equipped with the 2.0-liter turbocharged diesel engines with unauthorized software that tricked pollution tests.

The software device switched off after testing, enabling the vehicles to spew nitrogen oxides out the tailpipe.

The fine was the highest the antitrust arm could levy against VW for “misinforming” consumers about the company’s diesel emissions results.

Volkswagen told Reuters it plans to challenge the fine at an administrative court.

VW and its Italian division “have fully cooperated with the utmost openness and transparency” to help ascertain the facts, the carmaker said and “are certain that the decision presents well-founded grounds of appeal”.

“Volkswagen continues to take the view that it has duly complied with disclosure rules related to securities law,” a VW the spokesman said.

SEE ALSO: Volkswagen Reaches Preliminary Settlement in Federal Court Over Diesel-Emissions Scandal

A settlement last month with U.S. federal and state regulators put VW on the hook for $14.7 billion in fines and fees related to the scandal.

The company is involved in similar negotiations in North America, Asia and Europe, including its home country of Germany.

Additionally, investors who allege VW failed to disclose the diesel emissions cheating in a timely manner have filed 170 lawsuits seeking nearly $4 billion in damages.

On top of that, we reported yesterday that U.S. officials have discovered new emissions cheating software on the 3.0-liter diesel engines made by Audi used in three SUV models.

That fiasco will take several months to sort out.

Despite all the world-wide negative publicity related to the diesel wrongs, VW is now again the global sales leader.

While sales have declined in some markets, notably the U.S., where it can’t sell diesel models, VW somehow sold 1.5 million cars, SUVs and trucks the first half of this year, a 1.5 percent increase.