When pop legend Michael Jackson died on Thursday  (25 June), he left behind multiple lawsuits that are pending against, and some brought on behalf of, himself and his production company, MJJ Productions.

Lawyers handling those cases are spread across the country, managing everything from breach-of-contract disputes to employee claims to copyright infringement, writes The National Law Journal. It is unclear who would represent Jackson's estate in the litigation.

"I imagine this is going to be a very complicated engagement – the competing claims, the uncertainty and who might owe what to whom," said Jerry Hawxhurst, a partner at Baker Marquart Crone & Hawxhurst in Los Angeles. Hawxhurst represents Julien's Auction House, which Jackson's company sued in March to stop the sale of more than 2,000 of his personal items at Neverland Ranch.

The auction was canceled and the parties settled the lawsuit. In May, Hawxhurst brought an inter-pleader action against Jackson's company to sort out confusion over who at MJJ Productions is handling the dispute. That action is pending.

"Now, who knows?" Hawxhurst said. "It's probably going to stall while they work out the estate issues."

Alan Gutman, a solo practitioner  in Beverly Hills, who represents MJJ Productions in the auction case, did not return a call for comment.

Litigation involving MJJ Productions will be affected the least, since Jackson, not his company, died, said Andy Katzenstein, a partner in the personal planning department of Proskauer Rose  who works with several entertainment firms in Los Angeles. If Jackson is sued personally, however, that could raise difficulties, he said.

"There's nobody to speak for the estate yet… and it depends on whether he had a will or a living trust as to whether or not – and when – somebody will be appointed to speak on behalf of him," he said.

While most entertainers have living trusts, a will could delay pending litigation because the shift in management of his estate could take several months, he said.

Another pending suit involves claims brought by AllGood Entertainment, a New Jersey concert promoter that sued Jackson for $20m (£12.5m). AllGood alleges that Jackson reneged on his contract when he signed a deal with AEG Live to promote his shows in London.

AllGood's lawyer, Ira Scot Meyerowitz, a partner at Meyerowitz Jekielek in New York, did not return a call for comment.

Another suit involves Jackson's former manager, Raymone Bain, who sued for $44m (£27.5m) in profits that she claims she is owed under a contract with Jackson. Bain's lawyer, Frederick Samuels, a partner at Cahn & Samuels  in Washington DC, did not return a call for comment. Jackson's lawyer in that case is Londell McMillan, who heads the entertainment, media and sports group at New York's Dewey & LeBoeuf.

Broadcast Music has brought several copyright infringement claims on behalf of MJJ Productions and Jackson, primarily against popular bars and restaurants across the nation. Court records show that lawyers handling some of those claims for BMI include Betty Morgan, a partner at Cantor Colburn; Elliot Salter, a partner at Salter & Michaelson; Meg Boulware, a partner at Baker & McKenzie in Houston; and Courtney Holohan, a partner at Kirkland & Ellis.

Judith Saffer, assistant general counsel of BMI, said that the singer's copyrights will transfer to Jackson's estate. His death, she said, "will have no effect on this litigation".

Jackson's list of civil litigators is vast and has changed often in recent years.

"It's been bounced around to any number of lawyers," said Zia Modabber, chairman of the litigation department in the Los Angeles office of Katten Muchin Rosenman, whose firm handled Jackson's litigation from 1993 to 2004. "I'm not aware of any consistent lawyer or law firm handling this litigation over the past several years."

John Branca, a partner at Ziffren Brittenham Branca Fischer Gilbert-Lurie Stiffelman Cook Johnson Lande & Wolf  in Los Angeles, has been Jackson's general counsel and transactional attorney for years. Branca did not return a call for comment. But Modabber said that during the mid- and late 1990s, Katten Muchin handled some corporate work, such as trademark disputes, but primarily dealt with litigation involving concert promoters, employment actions and breach of contract claims.

"Michael got sued a lot," Modabber said. "During that time, I'm sure he had open and active cases the entire time."

The National Law Journal is a US sister title of Legal Week.