He jumps out of helicopters, goes naked on his yacht in the Mediterranean and is a James Bond-level Casanova. Would you want this man running your company?

Gianni Agnelli was a restless, seductive Italian aristocrat and industrialist. For three decades, starting in the 1960s, he reigned over Fiat, the manufacturing and auto giant founded by his grandfather in 1899 in Turin.

“Agnelli,” a documentary premiering Dec. 18 on HBO, remembers Fiat’s charismatic leader and his colorful life. It also reflects how the mores for the corporate elite have changed since his heyday.

In his native Italy, Agnelli’s rakish reputation added to his mystique. At his death in 2003, at age 81, flags across the country flew at half mast. But the HBO documentary arrives in very different era, one in which public figures face more intense scrutiny, sparked in part by sexual-harassment allegations against businessmen, entertainers, politicians and others. Taki Theodoracopulos, a friend of Agnelli, says the Fiat chairman and president “never forced himself on any woman.”

“I think it was a different time in terms of the paparazzi and the press,” with some of Agnelli’s escapades kept out of the spotlight, says Graydon Carter, the documentary’s executive producer. By contrast, “today, everything’s out in the open.”