Michael Jackson's mother Katherine Jackson, who had been granted limited control of the late singer's estate, was dealt a setback by a California judge on Monday.

Los Angeles Superior Court Judge Mitchell Beckloff denied Katherine Jackson's petition to delay the naming of attorney John Branca and music executive John McClain as administrators to shepherd Jackson's estate into a private trust.

"Mr. Branca and Mr. McClain for the next month are at the helm of the ship," Beckloff said.

The judge made his ruling "without prejudice," set bond at $1 million (the amount each side can use to perform discovery related to the will), and scheduled a court date for the parties to meet again on August 3.

RAW DATA: Unedited Back-and-Forth at Monday's Court Hearing.

Katherine Jackson's attorneys had asked that she be appointed to serve as a co-administrator with Branca and McClain.

Beckloff denied request, but stressed that Katherine Jackson should be given complete information about major transactions.

Katherine Jackson's attorneys also argued in vain that another, more recent will may exist, and that since Branca's firm had drafted Jackson's will, it would have undue benefit to Branca.

They said Katherine Jackson was concerned that Branca had been fired by Jackson in 2006, and had only recently been reinstated by the singer.

Attorneys for Branca and McClain countered that an exhaustive search for another will had been performed and turned up nothing. They also noted that McClain had been a friend of the family for 40 years, and that Branca had been Jackson's attorney for 30 years, so it was "not like Katherine didn't know them."

In making his ruling, the judge also dismissed Jackson's concerns that a seven-year-old will was too old, saying the document's age was "not out of the ordinary."

FULL COVERAGE: Click for complete FOX News coverage of Michael Jackson's death.

Monday's hearing was seen as crucial in deciding who takes control of Jackson's financial empire. Jackson died June 25, deeply in debt. But a court filing estimates that his estate will be worth more than $500 million.

A judge on Thursday delayed a hearing on who should have custody of Jackson's three children, making Monday's hearing entirely about the singer's fortune.

"This is going to be a very important hearing in the sense of giving the public an indication of where the case is heading and what the judge is thinking about," said Lawrence Heller, an estate planning attorney for the Santa Monica office of the firm Bryan Cave LLP.

Last week, Katherine Jackson was given authority over some of her son's possessions, including items taken from his Neverland Ranch that were slated for auction earlier this year, but not his finances. She had sought to control Jackson's finances and the estate of his children, but that was before Branca and McClain filed the will.

Beckloff, perhaps sensing a rift between the two sides, urged attorneys for Katherine Jackson and the two men to meet before Monday's hearing and try to reach a compromise.

Gaining even temporary control of Jackson's estate is key, attorneys for Branca and McClain argued in court filings, because they can begin tapping into the singer's earning potential by licensing "records, music, TV, publishing, pay-per-view, theatrical" properties.

Temporary administrators would also control 2,000 items taken from Neverland Ranch that were slated for an auction halted by the singer this year. The items, which include awards, clothing and numerous other unique items taken from Jackson's former home, were expected to fetch at least $12 million.

The Associated Press contributed to this report.