Freshfields Bruckhaus Deringer has taken a lead role on the $4bn (£3.06bn) sale of mixed martial arts (MMA) company, Ultimate Fighting Championship (UFC).

Milbank Tweed Hadley & McCloy, Simpson Thacher & Bartlett, Kirkland & Ellis, Proskauer Rose, and Paul Weiss Rifkind Wharton & Garrison have also secured roles on the sports deal.

A handful of private buyers have agreed to purchase the UFC – bought for a mere $2m in 2001 by casino moguls Frank and Lorenzo Fertitta – for $4bn. The deal comes two days after UFC 200, a signature event in the MMA arena, was held in Las Vegas.

Freshfields is acting for MSD Capital and MSD's partners, one of a number of investors led by the main buyer, WME | IMG, which will also serve as UFC's operating partner. The firm's team includes corporate partners Mitchell Presser, Doug Bacon and Paul Humphreys as well as finance partners David Almroth and Kyle Lakin.

UFC fights are shown worldwide and the competition has made a number of fighters into household names and millionaires, such as Ireland's Conor McGregor and Ronda Rousey of the US. In March, McGregor became the first MMA fighter to take home $1m, earned from his UFC 196 fight against America's Nate Diaz.

Milbank, which has enjoyed a longtime client relationship with the Fertitta brothers and Zuffa LLC – the Vegas-based entity controlled by the brothers, who own UFC – is advising the company on its sale to Beverly Hills, California-based talent agency William Morris Endeavor Entertainment (WME) and its private equity backers (KKR & Co, Silver Lake Partners and personal computer magnate Michael Dell's family office MSD Capital and MSD Partners).

Kenneth Baronsky, managing partner of Milbank's Los Angeles office and head of the firm's corporate practice in the city, has taken the lead on the deal at the firm, along with fellow corporate partner Adam Moses.

Neither lawyer was immediately available to discuss exact terms of the transaction, which were not disclosed, but Baronsky said in a statement that it had been "exciting to witness the evolution of the sport and the business" in the 15 years since the firm initially advised the Fertittas on their purchase of UFC.

"Milbank is pleased to play a key role in this important milestone as UFC moves into the hands of an accomplished and talented new ownership group that shares a vision and passion for the sport and is committed to taking UFC to the next level," added Baronsky. The Fertittas will retain a minority stake in UFC, as will the organisation's president Dana White, who will stay on in a top leadership role.

Other Milbank lawyers working on the matter include corporate finance partner Deborah Conrad, tax partner Russell Kestenbaum and employee benefits partner Manan "Mike" Shah.

UFC's COO Ike Lawrence Epstein, a former partner at Am Law 200 firm Lewis Roca Rothgerber Christie, previously served as UFC's general counsel. Kirk Hendrick serves as chief legal officer for Zuffa.

Paul Weiss corporate partner Justin Hamill and tax co-chair Jeffrey Samuels are leading a team from the firm representing WME on its acquisition of UFC, along with entertainment chair and IP group head Charles Googe and employee benefits and executive compensation partner Lawrence Witdorchic.

Simpson Thacher is serving as M&A counsel to its longtime California-based private equity client Silver Lake on its direct investment in UFC. The firm is also serving as primary finance counsel to the acquirers on the transaction.

Kirkland & Ellis and Proskauer Rose are advising New York-based KKR on its strategic investment in UFC. Kirkland corporate partners Sean Rodgers and Ravi Agarwal have taken the lead on the transaction, working closely with partners advising on tax, executive compensation debt finance and capital markets.