Fanatics is buying Mitchell & Ness, a fellow sports merchandiser.

Fanatics, known for its sports apparel and more, has teamed up with a host of celebrities, including the rapper Jay-Z and the D’Amelio family of TikTok fame, to buy the brand merchandising company Mitchell & Ness in its latest deal to expand its sports merchandise empire.

The deal, which closed on Wednesday, valued Mitchell & Ness at about $250 million, said two people with knowledge of the matter, who requested anonymity because the terms of the deal were confidential. Mitchell & Ness made about $70 million in profit off about $350 million in revenue last year, these people said.

Fanatics will own 75 percent of Mitchell & Ness as part of the transaction, while the other 25 percent will be owned by the celebrity cohort, which also includes Maverick Carter, LeBron James’s business partner, and the rapper Meek Mill. Kevin Wulff, the chief executive of Mitchell & Ness, will stay on as part of the deal, as will all 132 employees.

Fanatics has made its name by taking a fast-fashion approach to sports merchandise, setting itself up to quickly produce the hottest items by sensing shifts in fan demand. It owns the rights to fan gear for major U.S. sports teams, and the deal adds streetwear to a portfolio of apparel lines that include Majestic (jerseys), Top of the World (hats) and WinCraft (flags, banners and accessories).

More recently, Fanatics, which was last valued by investors at $18 billion, bought the trading cards business from Topps, and it has expanded into nonfungible tokens, the digital, tradable art more commonly known as NFTs, and gambling.

Mitchell & Ness, founded in Philadelphia in 1904, is known for its throwback jerseys, which go for $100 to $400. It already has licensing deals with the National Basketball Association, the National Football League, Major League Baseball, Major League Soccer and several N.C.A.A. schools.

The brand has changed hands several times, with Adidas acquiring it in 2007 and the private equity firm Juggernaut Capital Partners and Mr. Wulff buying it in 2016. It joins other nostalgia brands, like Reebok, that have brought in new owners with plans to bring new life into them.

Jay-Z, who described himself “an early adopter” of Mitchell & Ness, said in a statement that he was “proud to play a small role in bringing it back and, in some cases, introducing the authenticity and quality of the Mitchell & Ness brand to a new generation.”