Apple and rapper Eminem may be headed for trial on Thursday if they are unable to resolve a lawsuit over whether the singer's songs could be used on the popular iTunes service.

Eight Mile Style LLC, Eminem's music publisher, and another plaintiff, Martin Affiliated LLC, are claiming in a lawsuit in federal court in Detroit that Apple was never authorized to use 93 songs in a downloadable format on iTunes, court papers show.

Also being sued is Aftermath Records, which has control of Eminem recordings, and which the plaintiffs say had no right to enter agreements for digital downloads.

The plaintiffs have contended in court papers that Apple has provided and continues to provide digital downloading of recordings of compositions which Eight Mile and Martin are owners of, or have copyright ownership interest in, without obtaining permission or providing compensation.

In contrast, the defendants have said authorization for the downloads had been granted, and that Eminem's publisher has received substantial royalties on the songs, court papers show.

It was not clear how much money Eminem's publisher could recover. Among the songs at issue is Lose Yourself, a hit from Eminem's 2002 film 8 Mile.

Lawyers for the parties did not immediately return calls seeking a comment. A conference that could lead to a trial being averted was scheduled for Wednesday before U.S. Magistrate Judge Virginia Morgan in Ann Arbor, Michigan, according to court records.

It was not clear if Eminem -- whose given name is Marshall Mathers -- would testify at a trial.

The case is Eight Mile Style LLC v. Apple Computer Inc, U.S. District Court, Eastern District of Michigan (Detroit), No. 07-13164.

(Reporting by Jonathan Stempel, editing by Maureen Bavdek)