Music stars lined up for Jackson memorial

"We are relatively pleased with Judge Beckloff's ruling this morning. He's taken the unusual step of requiring that Ms. Jackson be kept informed of the administration of his estate in this preliminary phase," said Burt Levitch, an attorney for Katherine Jackson.

A separate hearing over the guardianship of Michael Jackson's children has been postponed until July 13. In the meantime, Katherine Jackson has been named temporary guardian of Prince Michael Jackson Jr. 12, Paris Michael Katherine Jackson, 11, and Prince Michael Joseph Jackson, II, 7.

An attorney for Branca and McClain said they would carry out the pop star's wishes and maximize his estate's value.

The value remains an open question. Although the 2002 will valued Michael Jackson's holdings at more than $500 million, the singer was reported to be as much as $500 million in debt when he died unexpectedly.

Jackson owned one-half of Sony-ATV, which controls a music catalog that includes songs from The Beatles and has been valued as high as $1 billion. Jackson also owned a company that controlled the rights to music he recorded during his solo career, and its value is expected to rise over time.