Lululemon is suing Under Armour for copying the design of its four-strap bra

Lululemon is suing Under Armour for copying the design of its four-strap bra

Canadian yoga wear brand Lululemon Athletica is understood to be suing rival sportswear firm Under Armour over claims it has copied the four-strap design of its best-selling sports bras.

According to a lawsuit filed last week, Lululemon has accused Under Armour of using, and continuing to use, the claimed designs of Patents-in-Suit, without its permission, on the Armour Eclipse Low Impact, Armour Shape Low Impact, UA On the Move, and UA Printed Strappy Bra sports bras. All of the bras retail for less than Lululemon's original US$52 design.

"An ordinary observer will perceive the overall appearance of the designs of the infringing products to be substantially the same as the overall appearance of the designs of the patent-in-suit," the claim reads.

Lululemon is seeking an injunction to stop Under Armour from further infringing on the patent, along with "damages and/or disgorgement of Under Armour's profits from its infringing activities", as well as costs and attorneys' fees.

The move follows a similar one made by Lululemon around five years ago. The company sued Calvin Klein in 2012 for violating one of its yoga pants designs, which eventually resulted in the companies reaching a confidential settlement.

Lululemon declined to comment on the lawsuit, while a spokesperson for Under Armour said: "As a leading brand in the sports performance market, [we] take the intellectual property rights of others very seriously."

Lululemon is understood to have collected more than 50 design patents to date, according to the Daily Mail.

Last month, Lululemon acquired a stake in Canadian cycling apparel startup 7mesh Industries in a move designed to "push the boundaries" in advanced technical apparel.

Lululemon takes stake in technical apparel specialist