By a 2-1 vote, the 2nd U.S. Circuit Court of Appeals agreed that the conspiracy violated federal antitrust law, and that the judge acted properly two years ago in imposing an injunction to prevent a recurrence.
The ruling would force Apple to pay consumers $450 million under a 2014 settlement of a class action with 33 state attorneys general and lawyers, unless it files another appeal and wins. The settlement was contingent on Apple's civil liability being upheld.
"While we want to put this behind us, the case is about principles and values," Apple said in a statement.

"We know we did nothing wrong back in 2010 and are assessing next steps," the company said.
Writing for the majority, Circuit Judge Debra Ann Livingston said Apple's actions "unreasonably restrained trade," rejecting arguments that the company acted independently with its own business interests in mind.
"The district court did not err in concluding that Apple was more than an innocent bystander," Livingston wrote.