BRUSSELS — It was a good day for Kit Kat copycats.

Nestlé, which makes the candy bar outside the United States, could lose exclusive rights in the European Union to its four-fingered shape, the region’s highest court ruled on Wednesday.

The company has long argued that the Kit Kat’s four trapezoidal bars, linked by a rectangular base, had enough of a “distinctive character” that they deserved a trademark across Europe.

The European Court of Justice, however, told Nestlé that it had not presented evidence that shoppers in Belgium, Greece, Ireland or Portugal would recognize a Kit Kat by shape alone.

“The main takeaway of the Kit Kat decision,” said Rachel Wilkinson-Duffy, a senior trademark attorney at the global law firm Baker McKenzie, was that companies would find it more difficult to get protection across the bloc for “unconventional trade marks such as shapes.”