The mayor of London has named two prominent business leaders to help shape preparations for the city's 2012 Olympics.
Justin King, chief executive of Sainsbury's, and David Gregson, a private equity investor, have both been appointed to advisory roles.
The new appointments come after Carphone Warehouse founder David Ross was forced to step aside last year.
Mr Ross quit his Olympic advisory role for personal reasons in December.
Mayor Boris Johnson said the new advisors would be charged with delivering an "exceptional" Olympic Games.
"My team and I are fully focused on guaranteeing that London hosts a spectacular sporting event for athletes and spectators alike in 2012," Mr Johnson said.
Mr King will become the mayor's representative on the board of the organising committee for 2012 (LOCOG), while Mr Gregson will chair the mayor's legacy board of advisors that aims to ensure the Olympics delivers long-lasting benefits to Londoners.
Mr Gregson, part-time chairman of Phoenix Equity Partners, said he hoped to draw on both his professional and charitable experience.
"I am greatly looking forward to getting started in the new role," he said.
Mr King said: "I feel excited and privileged to be asked to make a contribution to such an important event, for London and the country."
The announcement comes as organisers gave an update of progress on the building site in east London.
The Olympic Delivery Authority (ODA) has published new images from the site in Stratford.
Most of the 500-acre complex has now been cleared and work has begun on its Aquatics Centre and Olympic Village.