Steve Gordon, an entertainment lawyer and author of "The Future of the Music Business," worked at Sony Music during the 1990s. He said he was at Sony when Jackson's last contract was negotiated, though he acknowledged it could have recently been updated.

Gordon said Jackson owns some of his master recordings, while others are owned in partnership with Sony. Regardless, he said, Sony retains exclusive distribution rights for anything Jackson produced during the term of their contract.

Gordon said he expects Sony's Legacy Recordings division to do something similar to what it did with Elvis and create a division purely for Jackson's catalog.

"They've done every kind of configuration to try to squeeze more money out of the catalog with Elvis and they'll do it with Michael Jackson _ be sure of it," Gordon said. "I imagine that there's a ... load of concert recordings that may or may not have been released."

Jackson's last original album was 2001's "Invincible." His 2005 child molestation trial and other controversies distracted him from recording, but he was active in recent years.

He died just weeks before he was to perform 50 concerts at London's O2 arena in what was supposed to be his comeback. He had also begun working on new material.

Two weeks before he died, he wrapped up work on an elaborate production dubbed the "Dome Project," which could be the final finished video piece overseen by Jackson. Two people with knowledge of the project confirmed its existence Monday to The Associated Press on condition they not be identified because they signed confidentiality agreements.

Four sets were constructed for Jackson's production, including a cemetery recalling his famous "Thriller" video. Shooting for the project lasted from June 1 to June 9. Now in post-production, the project is expected to be completed next month.

Last year, Jackson released "Thriller 25," an album marking the 25th anniversary of the album. It included the new song "For All Time," as well as five remixes that involved will.i.am, Kanye West, Akon and Fergie.

The Black Eyed Peas frontman will.i.am has said he and Jackson recorded several songs together. He told the BBC on Monday that Jackson had possession of their demos, and that the songs "demanded all the people to the dance floor."