June 29 (Bloomberg) -- Michael Jackson’s mother, Katherine Jackson, was granted temporary custody of his three children by a Los Angeles court as she and her husband sought interim control over the late singer’s estate.

Michael Joseph Jackson Jr., 12, Paris-Michael Katherine Jackson, 11, and Prince Michael Jackson II, 7, are in their grandmother’s care, according to filings today in Los Angeles Superior Court.

Joseph and Katherine Jackson also asked to be named administrators of the estate, citing California probate law. The family hasn’t seen a will, Joseph Jackson told reporters today in a news conference outside his home. The singer’s assets can’t be quantified at this time, the family said in the filings.

“Mrs. Jackson is asking to be appointed the representative of the estate under the assumption there is no will,” said Lawrence Heller, an attorney at Bryan Cave LLP in Los Angeles, who has created trusts and estates for celebrity clients and has no role in the Jackson case. “If a will materializes, her petition would most likely be knocked out.”

The estate’s assets would be used only for the children, who are the sole beneficiaries under state law, the Jacksons said in the documents.

Jackson, the self-proclaimed “King of Pop,” died on June 25 at the age of 50 after suffering cardiac arrest in his home in the Los Angeles suburb of Bel-Air. He has no surviving spouse or domestic partner, according to the filings. The county coroner is awaiting toxicology tests before determining a cause of death.

‘Virtually Impossible’

“Public scrutiny of these proceedings makes it virtually impossible for the proposed administrator to do anything inappropriate with estate assets or in any manner harm the estate’s beneficiaries or creditors,” the Jacksons said in the filings.

Michael Jackson’s assets include interests in songs by the Beatles, Bob Dylan and others, as well as the Neverland Ranch near Santa Barbara, California, along with undetermined debt.

In 2006, the singer gave Tokyo-based Sony Corp. an option to buy half of his 50 percent stake in Sony/ATV, allowing the singer to refinance $300 million of loans.

In the probate filing, Joseph Jackson and his wife checked a box saying their son died without a will. The elder Jackson also said the family wants to see results of a second, private autopsy before scheduling services.

“We haven’t decided what’s going to happen at the funeral,” said the Rev. Al Sharpton, standing alongside Jackson.

Custody Petition

The custody petition sets up a potential conflict with Michael Jackson’s ex-wife, Debbie Rowe, the mother of his two oldest children.

Rowe at one time sued the singer over their custody arrangement before settling out of court for undisclosed terms, the Los Angeles Times reported today. Rowe must be notified 15 days before a custody hearing scheduled for Aug. 3, according to court documents.

Rowe’s lawyer, Marta Beth Almli, an attorney at Brown Woods George LLP in Los Angeles, wasn’t immediately available to comment.

Rowe asked “that Michael’s family, and particularly the children, be spared such harmful, sensationalist speculation and that they be able to say goodbye to their loved one in peace,” according to a statement released by Almli on June 27, the Associated Press reported.

‘No Relationship’

The youngest child, Prince Michael, was born to a surrogate mother whose identity hasn’t been made public, the Los Angeles Times reported.

The children “have no relationship with their biological mother,” according to the filings. The Jacksons also asked for temporary care, maintenance and support for their grandchildren. A hearing on the estate was set for July 6.

“They have a long-established relationship with paternal grandmother and are comfortable in her care,” according to the petition.

Katherine Jackson’s attorney, Diane M. Goodman of Encino, California-based Goodman & Metz, didn’t respond to requests for comment. Burt Levitch, of Rosenfeld, Meyer, & Susman LLP in Beverly Hills, California, is also representing the Jacksons.

To contact the reporter on this story: Andy Fixmer in Los Angeles at afixmer@bloomberg.net

Last Updated: June 29, 2009 18:12 EDT