The Justice Department said on Monday that it planned to overturn antitrust-related movie distribution rules from the early days of Hollywood, citing an entertainment landscape that has been radically reshaped by technology.

“We cannot pretend that the business of film distribution and exhibition remains the same,” Makan Delrahim, the antitrust chief at the Justice Department, said at an American Bar Association conference in Washington. “Changes over the course of more than half a century also have made it unlikely that the remaining defendants can reinstate their cartel.”

The film distribution rules, known as the Paramount consent decrees, were enacted in 1949, a year after the United States Supreme Court ruled that Hollywood’s eight largest studios could not own theaters, and thus control the film business. The regulations made it illegal for studios to unreasonably limit the number of theaters in one geographical area that could play a movie. They also banned “block booking,” a bundling practice where studios forced theaters to play their bad movies along with their good ones or not play any.

But that was when “metropolitan areas generally had a single movie theater with one screen that showed a single movie at a time,” Mr. Delrahim said. “Today, not only do our metropolitan areas have many multiplex cinemas showing films from different distributors, but much of our movie-watching is not in theaters at all.” In essence, he was saying that the regulations are obsolete because of technological advancements, most recently streaming.