According to lasvegasnow.com the Las Vegas-based UFC, a mixed-martial arts empire, has been sold for $4 billion; and this time, it's for real.

Stories about a possible sale have surfaced for the last two months, but each time the purported deals collapsed. However, this time, 8 News Now has learned, the papers were signed on Saturday.The price tag makes this the largest single deal in the history of sports, according to sources close to the situation.

Lorenzo and Frank Fertitta, the brothers who own 80% of UFC, originally purchased the sports network for $2 million. The Fertittas will retain a small percentage in the new ownership group.

The new owners include an alphabet-soup partnership of WME (William Morris Endeavor), the internationally known talent agency, IMG (International Management Group) a global sports and entertainment company based in New York, and MSD, a private equity group headed by Michael Dell. Also involved as a strategic partner is KKR, a global investment firm.

According to persons familiar with the deal, Lorenzo Fertitta will remain as chairman of UFC for 6-8 weeks during the transition but will step down after that. UFC president Dana White, who currently owns 9% of the organization, will continue in his role with UFC and will have a smaller ownership stake.