LOS ANGELES — In less than 16 years, the UFC has grown from a money-losing company in a widely reviled sport into a global entertainment property worth $4 billion.

While the UFC and its new owners figure out the company’s next steps, Lorenzo and Frank Fertitta are tapping out of mixed martial arts with a remarkable return on a $2 million investment.

The UFC was sold for about $4 billion to a group led by the Hollywood entertainment conglomerate WME-IMG, both companies confirmed Monday.

The sale will spectacularly benefit the Fertitta brothers and the UFC president, Dana White, who first persuaded his wealthy high school buddies to buy the cage fighting promotion in 2001. White, a Hermon High graduate who maintains a home in Maine, also owned 9 percent of the company and isn’t going anywhere despite his own windfall: He’ll remain the boss and public face of the UFC while keeping an ownership stake.

“No other sport compares to UFC,” White said. “Our goal has always been to put on the biggest and the best fights for our fans, and to make this the biggest sport in the world. I’m looking forward to working with WME-IMG to continue to take this sport to the next level.”

Since their purchase of IMG three years ago, the WME co-CEOs, Ari Emanuel and Patrick Whitesell, have been pursuing properties throughout sports and entertainment ahead of a possible initial public offering. The UFC is their biggest buy yet, and the deal appears to be the largest single financial transaction in the history of sports.

“We’re now committed to pursuing new opportunities for UFC and its talented athletes to ensure the sport’s continued growth and success on a global scale,” Emanuel said.

In their first public comments about the deal, White and the new owners have suggested little will change at first for the promotion. The UFC has a full slate of fights scheduled this year, all building toward its long-awaited debut at Madison Square Garden in November after New York legalized MMA earlier this year.