U.S. singer Michael Jackson, seen in London in March, announcing the concert series he never gave. (Joel Ryan/Associated Press)U.S. singer Michael Jackson, seen in London in March, announcing the concert series he never gave. (Joel Ryan/Associated Press)

A Michael Jackson tribute concert planned for London next year is in doubt after the Austrian company organizing it folded.

Vienna-based World Awards Media GmbH is now in liquidation after its main sponsor decided not to support it.

The company's chief promoter, Georg Kindel, said he has split with Christian Baha, majority owner of World Awards Media, and they decided in November to wind up the company.

Kindel was working with Jermaine Jackson, brother of Michael, in an attempt to create a tribute concert in London in June 2010.

Plans had been sketchy, with artists slow to sign on for the tribute concert for the singer, who died June 25 in Los Angeles.

The concert originally was planned for Vienna, but was moved to London's Wembley Stadium. Jackson, known as the King of Pop, was in rehearsal for a series of London concerts at the time of his death.

Kindel said Friday that he didn't know if Jermaine Jackson would continue with concert plans.