LOS ANGELES: Michael Jackson named his mother as guardian of his children and named soul legend Diana Ross as a back-up, according to a will filed in court here Wednesday.

The five-page document registered in Los Angeles County Superior Court revealed the 50-year-old singer's assets were to be left in the Michael Jackson Family Trust. The terms of the trust were not disclosed.

Documents filed in addition to the 2002 will valued Jackson's estate at more than 500 million dollars, although it was not clear how that figure had been reached. Jackson was believed to be heavily in debt at the time of his death.

While Katherine Jackson was named as carer for the pop icon's children, soul legend Ross, 65, was named as guardian if the singer's mother died before him.

Three associates for Jackson — attorney John Branca, music executive John McClain and accountant Barry Siegel — were named co-executors of the will.

There was no mention anywhere of Jackson's father Joe in the will while the document also confirmed no provisions had been made for ex-wife Debbie Rowe.

"I have intentionally omitted to provide my former wife, Deborah Jean Rowe Jackson," Jackson stated in the will, which was dated July 7, 2002.

"If any of my children are minors at the time of my death, I nominate my mother, Katherine Jackson as guardian ...," Jackson added.

"If Katherine Jackson fails to survive me, or is unable or unwilling to act as guardian, I nominate Diana Ross as guardian..."

On Monday a court granted Katherine Jackson temporary guardianship of the singer's children, Prince Michael, 12, Paris, 11, and Prince Michael II, 7.

A hearing has been set for July 6.