While judges often fine-tune proposed class-action settlements, it is unusual for one to be entirely thrown out in favor of a trial.

“I cannot recall a judge saying in a class-action case that the amount of settlement is too low and you need to go back and go for broke at trial,” said Daniel Crane, who teaches antitrust law at the University of Michigan Law School. “This is very striking.”

The rejection of the settlement is a victory for one of the five original plaintiffs, Michael Devine, who had raised objections to the deal.

“I am pleased that this case again has the opportunity to achieve real justice for the members of the class,” Mr. Devine said in an interview. “My hope is that the companies will pay at least as much back to their employees as they gained from these illegal agreements. Only then will there be real incentive to them, and others, to respect the law.”

Three of the defendants — Google, Apple and Adobe — declined to comment. A spokesman for the fourth company, Intel, said, “We are disappointed that the court has rejected preliminary approval of an agreement that was negotiated at arm’s length over many months.”

Settlements were reached last year against three other defendants in the suit — Lucasfilm, Pixar and Intuit.

Joseph R. Saveri, a lawyer for the plaintiffs, said he could not comment because he was traveling and had not had a chance to review the order. Another plaintiff’s lawyer, Dean Harvey of the firm Lieff Cabraser Heimann & Bernstein, did not respond to a message requesting comment.