BRUSSELS (Reuters) - The European Commission referred Germany on Thursday to the European Court of Justice over a planned road toll that it says discriminates against foreign drivers.

Germany's parliament approved a law last year to introduce a road charging system that would have granted vehicles registered in Germany a corresponding deduction from their annual vehicle tax.

The system was set to have started this year but was postponed after Brussels challenged it on the grounds that foreign drivers would have to pay the toll with no compensation.

Under the plan, approved by the German parliament in March 2015, Germany would have charged foreign drivers up to 130 euros ($145.83) a year to use Germany's Autobahn highways, which until now have been free.

Drivers could also have bought short-term passes costing up to 30 euros for 10-day to two-month periods.

The Commission said that an EU country was free to introduce road charges for goods vehicles and passenger cars, but, if it wanted foreigners to pay, then the charges must apply to all.

It also said that the prices for short-term vignettes, intended for vehicles registered abroad, were disproportionately high in some cases.

"Despite numerous exchanges with the German authorities since November 2014, the Commission's fundamental concerns have not been addressed. The Commission is therefore referring Germany to the Court of Justice of the EU," the Commission said in a statement.

(Reporting by Marilyn Haigh and Philip Blenkinsop, Editing by Angus MacSwan)