Damages are due to be decided at a later date.
Singer Katy Perry has lost a trademark battle with an Australian fashion designer who was born with a differently spelt same name. According to a BBC report, Katie Perry, now known as Katie Taylor, filed a lawsuit against the pop star, claiming that her merchandise infringed the trademark she owned.
The media portal reported that a judge agreed that clothing sold for Katy's 2014 Australian tour did breach Katie's trademark.
Federal court judge Brigitte Markovic ruled that Katy Perry's company Kitty Purry partially infringed the trademark of Katie Taylor's business, which sells mostly clothes online, by promoting the singer's products through posts on social media, a court filing out on Thursday showed.
Damages are due to be decided at a later date.
"This is a tale of two women, two teenage dreams and one name," Markovic said in her judgment.
The judge dismissed a bid by the popstar seeking to cancel the Katie Perry trademark, Reuters reported.
Taylor, whose birth name was Katie Perry, called the verdict a "David and Goliath" win for small businesses.
"Not only have I fought myself, but I fought for small businesses in this country, many of them started by women, who can find themselves up against overseas entities who have much more financial power than we do," she said in a blog post.
Representatives of Katy Perry could not be immediately reached.
The tussle between the popstar and the Australian fashion designer over the homophonous name began in 2008 when Taylor registered the "Katie Perry" brand in Australia.
Katy Perry initially tried to block the registration and later engaged lawyers to try to force the designer to cease and forever desist from using the mark but later abandoned the move, Taylor said.