Under Armour has filed a trademark infringement lawsuit accusing an athletic apparel brand called Hotsuit of copying the Baltimore brand’s famous logo.

Denver-based Ageas Inc. has been advertising and selling Hotsuit-branded sports and fitness apparel, footwear and accessories stamped with a logo similar to the Under Armour’s black logo linking an upside down U with an A, the lawsuit says.

“Defendant’s copycat logo has already caused confusion and gives Defendant an unfair boost in the marketplace at the expense of both Under Armour and consumers,” says the lawsuit, filed Oct. 8 in U.S. District Court in Baltimore.

Hotsuit was founded in 1999 by businessman Schroeder Jo, according to the company’s website. Jo’s idea for a fashion-based line of “sauna suits,” jackets and pants using patented technology fabric, was modeled after plastic garments worn by professional boxers to reduce body weight, the website says. The brand also sells shirts, leggings, sneakers, accessories and other items designed to offer “redefined sports time and improved exercise efficiency,” a company announcement said in July.

Representatives of Hotsuit did not respond Tuesday to requests for comment on the lawsuit.

But its website says Hotsuit’s logo blends the letter H with an electronic watch code to signify “a story of time and efficiency.”

In the lawsuit, Under Armour argues Hotsuit’s continued use of its logos will cause confusion and deception and falsely suggest sponsorship by Under Amrour. The filing also accuses Ageas of submitting fraudulent trademark applications to use the logo on products such as backpacks, handbags and wallets.

“Since 1996, we have worked hard to deliver great product and build Under Armour into the strong, global brand that we are today,” the company said in a statement. “We have an obligation to enforce our rights against similar marks and prevent any confusion in the marketplace.”

The Baltimore brand is seeking damages and court orders prohibiting use of Ageas’ Hotsuit logo.

Under Armour has used its corporate trademark and logo on its apparel since 1996, featuring it prominently in advertising and packaging, on its website and in thousands of stores.

The logo has found its way as well onto billboards, into sports venues and into commercials, including during the Super Bowl, and is worn through endorsement deals by athletes and celebrities such as Olympian Michael Phelps, ski racer Lindsey Vonn, NBA star Stephen Curry and supermodel Gisele Bündchen, among others.

“For years, Under Armour has spent millions of dollars annually extensively advertising and promoting itself, its marks, and its products to the general public through virtually every available type of media, including print publications, signage, television, and the Internet,” the lawsuit says.