OSLO, Norway (AP) - Kevin Spacey will step in as co-host of next week's Nobel Peace Prize concert after Tommy Lee Jones was forced to withdraw for undisclosed personal reasons, organizers said.

Spacey will join Uma Thurman in hosting the Dec. 11 concert held in honor of this year's Nobel peace laureates, former Vice President Al Gore and representatives from the U.N.'s climate change panel.

Organizers on Wednesday released no other details about Jones' decision to withdraw. Jones was Gore's roommate when they were students at Harvard University.

The lineup of performers, announced earlier, includes Australian pop star Kylie Minogue, Alicia Keys, Annie Lennox and Melissa Etheridge, who won an Academy Award this year for the song "I Need to Wake Up," which was featured in Gore's environmental documentary "An Inconvenient Truth."

Spacey has won two Academy Awards, in 1996 for best supporting actor in "The Usual Suspects" and in 2000 as best actor in "American Beauty."

He is currently performing in London, making it easier for him to step in as concert co-host at short notice, a news release said.

Gore and the Intergovernmental Panel on Climate Change share the 2007 Nobel Peace Prize for their efforts to help spread awareness about man-made global warming.