Milchan became involved in the American movie business in 1977, after an introduction to American producer Elliot Kastner. Most notable among Milchan's film collaborations was his early work with Martin Scorsese. He developed close friendships with Robert De Niro, and directors Roman Polanski, Sergio Leone, Terry Gilliam and Oliver Stone. Milchan started his own production company in 1991 called New Regency Productions. Through his company Regency, in partnership with Warner Brothers, and later with Rupert Murdoch at 20th Century Fox, and other business ventures, such as Puma AG, Milchan acquired a net worth estimated at about $5.1 billion .