US District Judge Yvonne Gonzalez Rogers had ordered Apple to lower the barriers protecting its previously exclusive payment system for in-app digital transactions and allow developers to display links to alternative options.
On Wednesday, she found that Apple violated a 2021 injunction that, she wrote, sought to "restrain and prohibit the iPhone maker's anti-competitive conduct" and pricing.
"Apple's continued attempts to interfere with competition will not be tolerated," Gonzalez Rogers wrote in Wednesday's ruling, which held Apple in contempt.
She ordered that Apple "no longer impede developers' ability to communicate with users nor will they levy or impose a new commission on off-app purchases".
Apple in a statement said "we strongly disagree with the decision. We will comply with the court's order and we will appeal."
Epic Games chief executive Tim Sweeney called the judge's order a significant win for developers and consumers, and said Epic Games would aim to bring back Fortnite to the Apple App Store next week.
Epic filed an antitrust lawsuit in 2020 alleging Apple had built an illegal monopoly around its popular App Store that makes billions of dollars annually from a then-exclusive payment system that collects commissions ranging from 15 per cent to 30 per cent on in-app commerce.
Although Gonzalez Rogers had rejected the monopoly claims, she ordered Apple to lower the barriers protecting its previously exclusive payment system for in-app digital transactions and allow developers to display links to alternative options.
The Supreme Court rejected Apple's appeal in the case in January 2024.
"In stark contrast to Apple's initial in-court testimony, contemporaneous business documents reveal that Apple knew exactly what it was doing and at every turn chose the most anti-competitive option," the judge wrote on Wednesday.
She accused Apple's vice-president of finance Alex Roman of "outright" lying under oath.
"Internally, (longtime Apple executive) Phillip Schiller had advocated that Apple comply with the injunction, but (CEO) Tim Cook ignored Schiller and instead allowed chief financial officer Luca Maestri and his finance team to convince him otherwise. Cook chose poorly," Gonzalez Rogers wrote.
The judge referred the matter to the US Attorney for the Northern District of California to investigate whether criminal contempt proceedings are appropriate.
Apple did not immediately respond to a request for comment on Wednesday.
with Reuters
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