The ODA has set up a portal, www.competefor.com, on which main contractors are contractually obliged to advertise their subcontracts if they do not have an existing supply chain.
"[Main stadium contractor] Sir Robert McAlpine has put five opportunities on the system," said ODA head of procurement Morag Stuart, speaking at NCE's Games Briefing conference last Wednesday.
"Yesterday Skanska put theirs on. Bovis Lend Lease will put theirs on. I think Skanska has another five to post next week."
The ODA has 250 major contracts above £20M to award by 2009 and sees the website as good way to open up access to small businesses and a diverse supply chain.
"If you're a big established contractor like Sir Robert McAlpine, you'll come with a degree of suppliers and we don't want to break up a chain that works," said Stuart.
"You'll probably have 70% to 80% of suppliers already identified. We're trying to capture that 20% which might go to Google search or recommendation."
Olympic village contractor Bovis Lend Lease has its own website – www.villagesupplychain.com – to advertise subcontracting opportunities on the project.
But Stuart said this was likely to merge with ODA's website in the next couple of months.
She added that 10,000 suppliers had already registered on competefor.com and buyers were starting to come online.
"The feedback we're getting is typically 10 to 50 people are applying for each opportunity," said Stuart.
The ODA wants its online system to be rolled out for public procurement spend by Transport for London, London Development Agency and London borough councils in the future.