The EU's Court of First Instance upheld a 2004 EU decision to cancel the brick's trademark status yesterday.
The trademark was registered in the EU in 1999, but rival Canadian toy firm Mega Brands successfully challenged it.
The EU's trademarks agency said the brick was a functional, technical shape that was not one company's property.
The ruling rejected Lego's claims that its bricks have special chacteristics that set them apart and ruled that Lego's two rows of studs on top of the brick performed a utilitarian function and were not 'for identification purposes in the trademark sense.'
EU trademark law 'precludes registration of any shape' that is 'sufficient to obtain the intended technical result.'
Lego had submitted details of consumer surveys showing most people identify the 2 x 4 red brick as the company's brand and that perception had to be taken into consideration when the judges made their ruling.