Procurement bosses have split the huge landscaping and remodelling job into two contracts covering the north and south of the 500-acre site in East London.
The whole transformation budget is £300m with this job worth more than £100m. The remaining £200m of work is already included in existing contracts.
Most of the works will involve bulk earthmoving and landscaping, although there will be significant dismantling with the removal of temporary structures and the central park bridge.
An ODA spokesman said: “This is not traditional demolition work it involves dismantling of the temporary structures.”
The winning contractors will be under the cosh to complete the job within the 12-month schedule before the site is renamed the Queen Elizabeth Olympic Park and reopened to the public in 2013.
The two winning contractors will be held responsible for all site logistics including security, protection and maintenance of the remaining games buildings.
Firms have until 4 April to prequalify using the ODA London 2012 e-Tendering Service at https://etenders.london2012.com/web/login.shtml.