Canada's highest court ruled unanimously Thursday that Mega Bloks does indeed have business in the playrooms of the nation, along with Lego.

The Supreme Court of Canada decision marks the end of a long-running trademark battle between the Montreal-based Mega Bloks and Denmark's Lego.

The ruling means that Montreal-based Mega Bloks (TSX:MB) can continue to sell its products in Canada.

Mega Bloks off the assembly line.

Lego Canada and Lego holding company Kirkbi AG first took Mega Bloks to court in 1996 over the bumps on the blocks, alleging Mega Blok's products were infringing on Lego's trademark.

Lego sought an injunction and damages from Mega Bloks. Lego believed it had a trademark on the look of the knobs on its blocks.

After losing in lower courts, Lego appealed the case to the country's top court. Lego argued that Mega Bloks' advertising of its blocks could cause confusion between the two companies' products.

'The monopoly on the bricks is over': Supreme Court

On Thursday, the Supreme Court justices concurred with a lower court judge who found that "purely functional" features, such as the well-known geometrical pattern of raised studs on the top of the bricks, could not be the basis of a trademark.

"Trademark law should not be used to perpetuate monopoly rights enjoyed under now-expired patents," the Supreme Court says.

The last of Lego's Canadian patents on its blocks expired in 1988.

"The fact is ... that the monopoly on the bricks is over, and Mega Bloks and Lego bricks may be interchangeable in the bins of the playrooms of the nation – dragons, castles and knights may be designed with them, without any distinction," the high court ruled.

Mega Bloks sells its products in more than 100 countries. Sales in the most recent quarter were $163.5 million. It made a profit of $20.4 million.

Shares of Mega Bloks finished up 49 cents, closing at $25.16 on the TSX.