City boys' shirtmaker Thomas Pink has put Victoria's Secret's knickers in a twist after winning a trademark battle against the US lingerie firm.

The high court ruled that Victoria's Secret had infringed the trademark of the shirtmaker, which takes its name from an 18th century London tailor, with the Pink lingerie brand which opened stores in the UK in 2012.

While Pink mainly sells colourful lingerie and casualwear for young women, its rival focuses on shirts and accessories for city slickers, both male and female. But the Jermyn Street-based British brand, now owned by luxury goods company LVMH, was not tickled pink by the possibility of confusion between the two brands. Judge Colin Birss ruled that the similarities could lead shoppers in Europe to associate Thomas Pink with "sexy, mass-market appeal" ladies' underwear which would cause a "detriment to the repute" of the shirt brand. "Consumers are likely to enter one of the claimant's shops looking for lingerie and be surprised and disappointed when they find they have made a mistake," Birss said. The court ruled that the shirtmaker's capital-lettered logo was valid because it had "acquired distinctiveness" among shoppers having been used on its shop fronts since 1984.

Matthew Dick, partner at D Young & Co, a law firm specialising in intellectual property, suggested Victoria's Secret may be forced to drop the pink trademark altogether in Europe. "Its use of the Pink mark in relation to clothing products (as different as lingerie aimed at college girls may be to Thomas Pink's more formal range of attire) was held to be unlawful – not only because it could lead to confusion in the marketplace, but also because such a mass market offering reduces the luxurious reputation of Thomas Pink's trademark," Dick said.