Canteen chairs don't often get noticed, but the 'B9' is a notable exception. When Bauhaus founder Walter Gropius fitted out the mess hall of the famous architecture college in Dessau with the elegant, curved stool back in the 1920s, he launched the career of a design classic.

Decades later, the humble seat is at the heart of an acrimonious legal tussle.

Tecta vs. Knoll

Tecta, a company based in the German state of Lower Saxony, is no longer allowed to sell the tubular steel stool it began marketing in 1982. Moreover, the court ordered the company hand over all its profits from sales of the chair -- as well as its matching table, the 'C4' -- to rival business Knoll International, which has an older claim to the design rights.

Knoll International sells a stool known as the 'Laccio,' which closely resembles Breuer's 1925 B9 model. Its sole difference is that while the B9 is sheer white, 'Laccio' is raven black.

Furniture feuds

The dispute over the highly lucrative licence for the B9 has been dragging on for years.

Tecta argues it owns the rights because it signed a contract with the Berlin Bauhaus Archive based on an agreement with Breuer's widow Constanze. In court, however, Knoll was able to go one further, producing contracts personally signed by Breuer in the 1960s. The company came into possession of the documents when almost 50 years ago it acquired Gavina, an Italian company which had bought the rights to the B9 from the designer himself.

Dino Gavina has revealed that the contract was considered valid for only ten years at the time of signing, which has prompted Tecta to announce it will file an appeal.

Not the first time

If so, it won't be the first time. Three years ago, the company won a legal battle with another company, L&C Stendal, which manufactured copies of the Breuer stool. In court, L&C Stendal argued that a stool is a household object rather than a work of art and therefore not subject to licencing laws.

In its final ruling, the court deemed the stool was indeed a work of art, and upheld the contract between Tecta and Breuer's heirs.

The battle over Breuer

One of the most influential designers of the 20th century, Breuer both studied and taught at Germany's Bauhaus school of architecture and design (photo), which pioneered modern principles, technologies and the application of new materials in both the industrial and fine arts.

An early fan of tubular steel, Breuer designed a whole range of metal furniture including chairs, tables, stools and cupboards. Breuer considered all of his designs to be essential for the masses and mass production of modern living. Many of his models, like the B9, became instant classics.

Exclusivity was probably the last thing on his mind.