LOS ANGELES - The promoters of what was to be Michael Jackson's 2009 comeback tour won a round in court today when a judge granted a motion to dismiss the company from a lawsuit filed by the singer's father.

"This was a major victory," AEG Live attorney Marvin Putnam said of Los Angeles Superior Court Judge Yvette Palazuelos' ruling.

The decision leaves Jackson's former physician, Dr. Conrad Murray, and Applied Pharmacy Services in Las Vegas as the remaining defendants.

Joe Jackson's attorney, Maureen Jaroscak, downplayed the significance of the ruling, saying it was only a temporary setback. She said her client is a "nominal party" in a separate case filed against AEG Live by his wife, Katherine Jackson, but that he was never served with it. Jaroscak said Joe Jackson could now file an answer to his wife's complaint and become a party to the case.

Joe Jackson alleged AEG Live was negligent in hiring Murray. He also alleges Applied Pharmacy Services sold Murray propofol the month before the singer's June 25, 2009, death at age 50.

Lawyers for AEG have denied any wrongdoing by their client, which organized the sold-out London concert tour for which the entertainer was preparing in Los Angeles when he died.

Murray was convicted Nov. 7 of involuntary manslaughter in Jackson's death and sentenced to four years in prison.

Attorneys for AEG Live questioned in court papers whether 83-year-old Joe Jackson

is a lawful heir to the King of Pop under the state's wrongful death statute, noting that Joe Jackson said in interviews that his son never supported him financially.

The singer was frank about his relationship with his father, the AEG Live court papers stated.

"At the time Michael Jackson died, (his father) was estranged from his son, who repeatedly and publicly accused him of physical and other abuse," according to the AEG Live court papers.

But the lawyers said that, even if Joe Jackson could show he was an heir, he should have included his claims within the negligence case against AEG Live brought in September 2010 by Katherine Jackson two months before he filed his own case.

"The law is well-established that all plaintiffs must join together in a single wrongful death action against any given defendant," the AEG Live court papers stated. "AEG Live will not speculate as to why (Joe Jackson) was not joined in, and did not seek to join, Mrs. Jackson's lawsuit."

Joe Jackson could still try and become a party to his wife's case, the AEG Live court papers stated. If he can prove that Katherine Jackson's lawyers improperly left him out of her case, he can ask for damages against her, according to the AEG Live court papers.

In her nine-page ruling, Palazuelos agreed with Putnam that there should be only one wrongful death action and not two.

"Allowing Joseph Jackson to continue with his subsequent suit against AEG Live, alleging the same wrongful death claims as the related case, would contravene the purpose of the one-action rule," Palazuelos wrote. "Indeed, plaintiff's interpretation of the one-action rule would allow the heirs of a decedent to file as many suits as there are heirs."

The judge reiterated her position during the hearing.

"I don't think there's any way around this," she said. "You can't maintain a concurrent action."

Palazuelos scheduled trial of Joseph Jackson's suit for Jan. 28 next year. Palazuelos also is managing Katherine Jackson's case, which is set for trial Sept. 10.

Katherine Jackson alleges in her suit that AEG Live is responsible for medical decisions made by Murray.