Apple can continue to ban Fortnite from its App Store but should not hamper Epic Games from providing software to other apps, a US court has ruled.

In an escalating battle over Apple’s App Store fees, US district judge Yvonne Gonzalez Rogers handed a partial victory to the iPhone maker, denying Epic’s request to temporarily reinstate Fortnite while the two battle in court.

But she warned Apple not to hurt other companies, who rely on Epic’s “Unreal Engine” software to make games, by revoking Epic’s access to the iPhone’s development ecosystem.

“Epic Games and Apple are at liberty to litigate against each other, but their dispute should not create havoc to bystanders,” she said.

Epic provoked Apple’s wrath by introducing a way for Fortnite players to spend money in the game without paying Apple a 30 per cent cut, a move that violated App Store guidelines.

Apple responded by banning Fortnite, the popular battle game, from the App Store, and threatening to remove Epic’s developer status.

As well as making games, Epic sells the Unreal Engine software platform, which many companies use to create their own games. Cutting Epic off from developer tools would prevent it from updating Unreal Engine, affecting thousands of other apps.

Microsoft, which makes the Xbox, uses the technology for games developed for consoles, PCs and mobile devices, and is backing Epic in court.

In the court order Judge Rogers said: “Apple has chosen to act severely, and by doing so, has impacted non-parties, and a third-party developer ecosystem. In this regard, the equities do weigh against Apple.”

The judge, who earlier noted that neither side had a “slam dunk” case, said “serious questions do exist” for Apple on potential antitrust abuses in its app store.

But she added that Epic “has not yet demonstrated irreparable harm” and that “the current predicament appears of its own making”.

She set a further court hearing for September 28.

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Fortnite is among the top grossing apps of all time, free to download but earning revenues estimated at $34m a month from in-app purchases of items such as tools and outfits.

Each company has said the stakes are high. Epic is arguing that Apple is a monopolist guilty of antitrust violations, because it “ties” App Store distribution with a payment system that demands a 30 per cent fee on all in-app purchases.

Apple argues these are not two products, but one — the payment mechanism is merely a digital checkout counter — and that it is “nothing approaching a monopolist”. Apple has said that if Epic were allowed to bypass its payment mechanism then the “entire App Store” business model would be at risk.