London Marathon organisers have promised to invest £3m over 10 years to ensure there is life after 2012 for the capital's Olympic Stadium.
The Lea Valley arena will be built if London wins the Games, but critics have voiced concern about its long-term use.
The London Marathon Trust has agreed to contribute £300,000 a year to guarantee the stadium would continue to be used for international athletics.
Bid chairman Sebastian Coe welcomed the pledge calling it "fantastic" news.
"We are very grateful for the support of the London Marathon," he added.
"And this is what winning an Olympic bid is all about - putting in place a lasting legacy and much-needed infrastructure, both for the local community and for our elite athletes."
John Disley, co-founder of the London Marathon, sees the planned funding as an ongoing investment in British sport.
"The Trust is extremely excited to be able to make a significant contribution to sporting facilities in London and the UK," he said.
"They will provide a focus for sporting excellence and will be managed for Londoners so that athletes striving for international success can inspire grass-roots participation."
As part of the post-2012 deal, it has been agreed that the stadium would be run by a not-for-profit organisation prepared to make the facilities available to the public.
The Olympic stadium would also have to retain a running track capable of hosting international events.
A 10-metre statue of an athlete representing British pride and honour will be erected in Trafalgar Square on Saturday 19 February as part of London's bid for the 2012 Games.