Participant Productions further demonstrated its credentials as one of Hollywood's most overtly political company by hiring event producer John Schreiber in the newly created position of executive vice president of social action and advocacy.

Schreiber 's prolific output includes organising White House gala events, Chinese cultural shows in New York and cause-related programmes for the American Museum of Natural History and Partnership For A Drug Free America.

He will immediately commence work on the upcoming release Chicago 10, Brett Morgen's documentary about the antiwar protests at the 1968 Chicago Democratic convention that opens Sundance tomorrow.

'An Emmy and Tony Award winning producer with extensive experience across media platforms, John Schreiber has spent his career creating entertainment properties where cause related and social action initiatives have always played an integral part,' Participant chief executive officer Jim Berk said.

'Participant provides John with the perfect opportunity to leverage his expertise and passion to expand our social action and advocacy campaigns.'

'As we grow the company, it's important that we round out our team with leaders in their respective fields,' Participant president Ricky Strauss said.

'By finding someone of John's unique talents we are confident that we are moving in the right direction, ever mindful of our mission to make a difference in the world.'

Schreiber also served as president of music festival producer Festival Productions, and The John Schreiber Group, an event marketing firm he operated for 10 years. Most recently he was president of Lafayette Productions, a joint venture with the Margeotes Fertitta Powell advertising agency.