Apple and Epic, in separate court filings, mounted challenges to a ruling by a three-judge panel of the San Francisco-based 9th U.S. Circuit Court of Appeals.
Lawyers for the two companies said the panel should rehear the case or the court should convene "en banc," as an 11-judge panel, to reconsider the dispute.
The April three-judge ruling upheld a 2021 order in California federal court in Epic's lawsuit which accused Apple of unlawfully requiring software developers to pay up to 30 per cent in commissions on consumers' in-app purchases.
The trial judge found that Apple violated a California state unfair competition law, not US antitrust provisions. Apple's new filing challenged a nationwide injunction over conduct Apple said was "pro-competitive and does not violate the antitrust laws."
Epic's 9th Circuit filing argued that its claims against Apple directly implicate the "core purpose" of U.S. antitrust law to foster competition. Epic also argued that the appeals court did not conduct a "rigorous" balancing between asserted consumer benefits and the anticompetitive effects of Apple's practices.