UFC, a mixed martial arts organization that was purchased in 2000 for $2 million, has been sold for a reported $4 billion in what would be among the largest transactions in history for a sports organization.

William Morris Endeavor, along with International Management Group, announced the sale of the organization, which is primarily owned by Lorenzo and Frank Fertitta, in a news release. Terms of the deal were not disclosed, although the Las Vegas CBS affiliate reported that the sales price was $4 billion. There has been little turnover in franchises lately, but the Los Angeles Clippers were sold in 2014 for $2 billion. The Los Angeles Dodgers brought the same price in 2012. In May, Forbes rated the Dallas Cowboys as sports’ most valuable franchise at $4 billion, with Real Madrid at $3.65 billion, Barcelona at $3.55 billion, the New York Yankees at $3.4 billion and Manchester United at $3.32 billion.

UFC President Dana White and Ari Emanuel, who is co-chief executive of one of the purchasers, had previously confirmed the sale to ESPN and the Associated Press after news of the eye-popping transaction broke Sunday night. In addition to WME-IMG (and its owner Silver Lake Partners), the new owners will be the private equity company KKR and MSD Capital, the investment firm of billionaire Michael Dell. WME-IMG is a leading talent agency and its clients include UFC superstar Ronda Rousey.

“We’ve been fortunate over the years to represent UFC and a number of its remarkable athletes,” WME-IMG co-CEOs Patrick Whitesell and Emanuel said in a joint statement statement on UFC.com. “It’s been exciting to watch the organization’s incredible growth over the last decade under the leadership of the Fertitta brothers, Dana White and their dedicated team. 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.”

Lorenzo Fertitta, the UFC CEO who purchased the company along with his brother Frank, is expected to remain as chairman through the transition. Fertitta and his brother Frank together own about 80 percent of the company. White, who owns about 9 percent of the company, is expected to retain an ownership stake. The Abu Dhabi government’s Flash Entertainment is a 10 percent owner of UFC, whose parent company is Zuffa LLC. (Zuffa is Italian for “fight.”)

In May, White had dismissed talk that a sale was imminent, telling the “Dan Patrick Show” that “we’re not up for sale.” And White reiterated that in an interview with the Los Angeles Times early last week.

“We’re always working on deals and our expansion globally,” White told Patrick in May. “I’ve been saying since this thing came out, no, we’re not for sale, but let me tell you what. If somebody shows up with $4 billion, we can talk. We can definitely talk.”

Well, somebody did and they did more than talk.

In the last decade of its 23-year history, UFC has become a global sports force, with the privately held company generating an estimated $600 million in revenue last year, and has attracted a growing audience of millennials, a group coveted by advertisers and TV networks. It says its fights are shown in more than 156 countries and its events are the top sellers on pay-per-view TV. The Fertittas, who made their first fortune as casino owners, estimate that 30 million to 40 million people watch their biggest pay-per-view events, according to the New York Times.

Over the weekend, UFC 200 drew more than 18,000 fans to T-Mobile Arena in Las Vegas despite the absence of Ronda Rousey and Conor McGregor, the sport’s biggest stars. The card, which also featured the crossover of WWE star Brock Lesnar, was thrown into disarray late last week when Jon Jones was scratched because he tested positive for an undisclosed substance.