Lord Sebastian Coe has revamped London's bid for the 2012 Olympics.
Lord Sebastian Coe is chair of London's 2012 Olympic bid team
The bid's chairman is making changes in response to criticisms by the International Olympic Committee (IOC) over the city's plans.
The IOC expressed concerns about the number of events planned outside Greater London and said the bid's transport plans were unclear.
Olympic consultants MI Associates will now help prepare the bid file to be submitted to the IOC in November.
The move means a suggested second athletes' village outside London and the rowing races in Berkshire could be scrapped.
And former chairman Barbara Cassani, who stepped down to take over Coe's vice-chairman role specifically to deal with the candidate file, drops further into the background.
Her role will now mainly be one of liaising with the board on technical matters.
Coe said: "We should leave no stone unturned in the pursuit of a winning bid.
"I believe we must improve on our proposals and we must aim to produce the best technical bid when we submit our candidate file to the IOC in November."
MI Associates is run by Jim Sloman, an Australian who was previously chief operating officer for the Sydney 2000 Olympics.
The company has also worked on the Sydney bid, Manchester 2002 and Melbourne 2006 Commonwealth Games, the 2007 Pan American Games and the Beijing 2008 Olympics.
The firm will now appoint a project manager to head a team working on the candidate file to produce detailed plans about the technical side of the bid.