The interim Olympic Delivery Authority (ODA) will reveal details of the first big 2012 Games contract today.
Construction companies with a turnover of at least £100m will be invited to tender.
The contract details are expected to indicate how the ODA, which is responsible for delivering the permanent venues and infrastructure projects for the Olympics, plans to avoid the setbacks that have plagued Wembley stadium.
Multiplex, the company working on the Wembley contract, has made an estimated loss of £180m on the project, including £14m in penalties for running behind schedule.
Balfour Beatty and Amec have already indicated that they intend to put in a joint bid for the Olympics contract.
The government has indicated that firms with good employment practices will be given preference.
