The Olympic Park Legacy Company, which is overseeing the process, said there were more than 100 companies interested in the east London arena.
Any organisations wishing to take over the stadium being built by Sir Robert McAlpine now have six weeks to make a formal bid.
West Ham Football Club and O2 arena owner AEG are believed to be the favourites.
West Ham will submit plans to spend £180m converting the 80,000 seater stadium into a Premier League football ground holding 60,000 which will also stage cricket matches, athletics meets and concerts.
Rival legacy plans involve dropping the capacity to 25,000 to form a permanent athletics venue.
The OPLC has said the winning bidder must retain the stadium as a “distinctive physical symbol” and support the regeneration of the area.
Once the bidding period ends on 30 September, the OPLC will select a shortlist.
Margaret Ford, chairwoman of the OPLC, said: “The stadium is at the heart of the Olympic Park and securing the solution is crucial to our long-term aspirations for the area.
“We aim to have selected a tenant by the end of the financial year.”