Her immediate challenge is to start new movies while honoring a thicket of remaining commitments to Paramount, which will distribute films that have already been made, like “The Soloist” and “Transformers: Revenge of the Fallen,” and still has the right to be involved with dozens of projects it acquired when it bought the company.

Mr. Geffen’s departure originally was planned more than a year ago, after he negotiated new terms with Paramount. He had a right to make an early exit from the studio if he chose  and Mr. Spielberg and Ms. Snider were entitled to leave behind him. What Mr. Geffen did after negotiating the deal, Mr. Spielberg said, caught him by surprise: He told Mr. Spielberg that he did, in fact, intend to leave. And he expected Mr. Spielberg and Ms. Snider to do the same.

“Where do we go?” Mr. Spielberg now recalls asking.

“Don’t worry, I will handle all of that,” Mr. Geffen said.

In any case, Mr. Geffen appears to have orphaned a small corps of associates who had come to view him as the central support for their own hopes and dreams.

In describing Mr. Geffen’s role at DreamWorks, Mr. Spielberg likened it to a family relationship. “Jeffrey and I were like the kids,” he said, while Mr. Geffen built the house and saw that the bills were paid.

Mr. Geffen’s legacy has included the sale of his record company to MCA; MCA’s eventual sale to the Japanese electronics giant Matsushita; a behind-the-scenes war on the once-powerful agent Michael S. Ovitz; and the highly public separation of the DreamWorks principals from Paramount after friction with that company’s chairman, Brad Grey. As a talent manager and record executive, Mr. Geffen helped build the careers of artists like Jackson Browne and Joni Mitchell. Though he personally produced only a handful of movies, including “Interview With the Vampire” in 1994, he was closely involved with many others, including “Risky Business” and “Dreamgirls.”

By his own recollection, Mr. Spielberg was initially reluctant to join in creating the original DreamWorks studio, which was conceived by Mr. Katzenberg shortly after he was fired as chairman of the Walt Disney Company’s studio operation in 1994. But Mr. Katzenberg begged for a meeting, and asked to bring a friend. The friend was Mr. Geffen, who not only did all the talking, but insisted to Mr. Spielberg: “I am representing your best interests.”