Retiring Mark Tuitert of the Netherlands after his last professional race at the men's 1500-meter speedskating race during the World Cup final at Thialf skating arena, March 15, 2014, in Heerenveen, northern Netherlands. (PHOTO / AP)

The International Skating Union (ISU) cannot penalize speed skaters if they compete in new money-spinning events, the European Union's top court said on Thursday as it upheld earlier orders.

The case centered on a complaint by Dutch Olympic speed skaters Mark Tuitert and Niels Kerstholt after ISU threats of a lifetime ban stopped them from competing in lucrative Ice Derby events run by a South Korean company.

The case could, for example, make it easier for unofficial and breakaway events and competitions to be set up without the approval of a sport's governing body

The European Commission in a 2017 ruling said the sport's governing body had imposed "disproportionately punitive" sanctions on skaters, preventing the emergence of rival events in violation of EU antitrust rules.

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The EU Court of Justice said ISU's rules that forbid skaters from taking part in any competition it does not organize are not transparent nor proportionate.

"They give the ISU a clear advantage over its competitors and have unfavorable effects for athletes as well as consumers and broadcast audiences," the court said.

Legal experts in sports-related cases have said the decision could affect other sports and become as significant as the 1995 court ruling involving Belgian soccer player Jean-Marc Bosman, which paved the way for the free movement of players in the EU.

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The case could, for example, make it easier for unofficial and breakaway events and competitions to be set up without the approval of a sport's governing body.