As expected, mixed-martial arts league, Ultimate Fighting Championship (UFC) has been acquired by a consortium of investors led by WME-IMG for approximately $4 billion. The companies are expected to make a formal announcement Monday.

The investors in the WME-IMG corner are understood to include Silver Lake Capital, Kohlberg Kravis Roberts and MSD Capital, the private equity pool controlled by computer billionaire Michael Dell.

The 23-year old company has been controlled by Frank and Lorenzo Fertitta. They now cede control, but stay on as minority investors. They held some 80% of the company, alongside a 10% stake owned by the Abu Dhabi government and UFC president Dana White.

Although the brothers repeatedly denied the sale talks, reports from the investment community repeatedly leaked details of the negotiations — including interest from the giant Chinese property to entertainment group Dalian Wanda. China Media Capital and The Blackstone Group had also been reported as bidders.

A rep for WME-IMG declined comment. White told ESPN that the change in ownership was “very bittersweet,” but sought to assure fans that the change was for the good. “Sport is going to the next level,” he told the channel.

The sports empire has been a triumph in the digital era. In addition to live events, its fights are available as pay-per-view content and are shown in over 150 countries. UFC also sell subscriptions via its Fight Pass SVOD service, which it launched in 2013.

The league has also helped make cross-over stars of fighters including Randy Couture and Ronda Rousey.

WME-IMG was formed in 2013 after Hollywood talent agency WME and Silver Lake together acquired sports and events management group for $2.4 billion. It is now seeking to become a major owner of content especially in the sports arena, and last year acquired the Professional Bull Riders league.