The European Court of Justice dismissed an appeal from Spanish cycling company Massi and the EU's intellectual property office, EUIPO.
The Barcelona footballer first applied to trademark his surname as a sportswear brand in 2011.
But Massi argued the similarity between their logos would cause confusion.
The European Court of Justice (ECJ) said that the star player's reputation could be taken into account when weighing up whether the public would be able to tell the difference between the two brands.
