The Lego brick, one of the most instantly recognised toys in the world, cannot be trademarked, European judges ruled today.
The Danish toymaker's basic red plastic brick was literally the building block for a global toy industry success.
The brick's three-dimensional 2x4 shape was registered as an EU trademark in 1999.
But rival Canadian maker Mega Brands, which markets Mega Bloks, successfully appealed to the EU's trademark office to cancel Lego's trademark. The trademark experts decreed that a brick was a functional, technical shape which could not be trademarked by any one company.
Lego lost an appeal two years ago, and now the European Court of Justice in Luxembourg has rejected Lego's latest application to have its trademark returned.
The firm challenged the idea that functional shapes, such as a brick or any other "industrial design", were necessarily excluded from trademark protection.
Lego, claimed the company's lawyers, contains characteristics that set it apart, such as the design and size of the studs on top of the bricks.
But the judges today ruled that keeping the Lego trademark on the basic brick design created a monopoly on what amounted to a functional shape which was "necessary to obtain a technical result".
They rejected Lego's claim that the company's competitors did not need to copy the shape of the Lego brick to achieve the same "technical solution", saying: "The Lego brick is not registrable as a Community trademark. It is a sign consisting exclusively of the shape of goods necessary to obtain a technical result."
An EU trademark could be in the form of words, designs, the shape of goods, or of their packaging, as long as the signs distinguish the product or service from those or rival firms, but the ruling added: "Signs which consist exclusively of the shape of goods which is necessary to obtain a technical result are not to be registered.
"The most important element of the sign composed of the Lego brick is the two rows of studs on the upper surface of that brick, which are necessary to obtain the intended technical result of the product, that is to say, the assembly of toy bricks."
Shireen Peermohamed, partner in the intellectual property practice at London law firm Harbottle & Lewis said the ruling marks the end of the road for Lego's trademark battle.
"The court appears to have been influenced by the public interest in ensuring that companies cannot use trademark law to secure a potential monopoly over technical solutions," she said.
"If Lego had been allowed to keep its brick registration it could potentially renew it indefinitely and thereby impede the use by others of the same or similar solutions.
"Interestingly, though, the court left open the possibility that Lego could take action under unfair competition laws to object to copies of its bricks. Lego's fight may thus not be over completely."