By Blake Brittain

June 15 (Reuters) - Deckers Outdoor Corp DECK.N failed to convince a jury in California federal court on Monday that Quince's "dupes" of its UGG boots infringed a patent covering the boot's design.

The jury declared the patent invalid and rejected Deckers' argument that Quince's version of the popular sheepskin UGG boots violated its intellectual property rights, a Quince attorney confirmed.

The trial is one of the first over the legality of "dupes" -- popular products that are advertised as low-cost equivalents to their brand-name counterparts. Quince, which specializes in dupes, says its mission is to "create products of equal or greater quality than the leading luxury brands at a much lower price."

Spokespeople and attorneys for Deckers did not immediately respond to a request for comment on the verdict.

"This case was never about an ankle boot," Quince Head of Legal Joel Dion said in a statement. "It was about whether one company can claim ownership of a common, category-wide design and use the courts to push out anyone who competes with it."

Deckers also owns footwear brands Hoka and Teva. It sued Quince in 2023 and accused it of infringing a design patent -- a type of U.S. patent that covers object designs instead of inventions -- covering the UGG Classic Ultra Mini boot.

Quince denied the allegations and argued the patent was invalid.

Deckers had previously argued that Quince also violated its trademark rights. U.S. District Judge Araceli Martinez-Olguin dismissed Deckers' trademark-related claims last year after finding the UGG design was too generic for trademark protection.

Williams-Sonoma filed a separate false-advertising lawsuit against Quince last year. Quince is also defending against a trademark-related lawsuit filed last year by Coach parent Tapestry for selling similar-looking handbags.