A US judge has ordered Apple to disclose details of its patent-sharing deal with HTC to its rival, Samsung.
Apple and HTC signed a 10-year licence agreement, external earlier this month, but did not make the details public.
Samsung, which is also involved in various patent disputes with Apple, asked the courts to tell Apple to furnish the information.
It said it was "almost certain" the deal covered some of the patents at the centre of its dispute with Apple.
The court ordered Apple to produce a full copy of the settlement agreement "without delay", subject to an "attorneys' eyes only" designation, meaning it will not be made public.
The deal between Apple and HTC saw the two firms settle all their outstanding disputes over patents, ending a fight that began in March 2010.
According to some reports, the two companies were fighting almost 20 cases across the globe.