By Adrian Warner
BBC London's Olympics Correspondent
An Olympics museum could be built under the stadium
The woman in charge of the legacy of the 2012 Olympics has revealed that she might revamp the plan to scale down the main stadium from 80,000 to 25,000 seats after the Games, especially if the arena becomes part of England's 2018 World Cup bid.
Baroness Ford said she and Olympics Minister Tessa Jowell accepted that the Olympic Park in Stratford, east London, must be left with a world-class athletics venue after 2012.
In her first television interview since taking office, Baroness Ford said: "It is cast in stone that we leave a Grand Prix athletics stadium.
"But what I have opened the book around is the other kind of value we can add to this stadium.
"If we won the World Cup bid, that would be one reason to keep the stadium at a particular capacity.
"Tessa and I agree that it is more important that we have a stadium built as an attraction.
"Whether it's 80,000, 50,000 or 25,000 seats after the Games is a kind of second question."
I have learned that there is increasing support for the stadium to be proposed as a ground for semi-final matches in 2018.
I think it will become a bit like Central Park in New York - beloved of New Yorkers but also a fantastic magnet for visitors to the city
That would mean it would stay at 80,000 so it could stage matches at the decisive end of the tournament.
So far everybody has assumed that the top tiers of the stadium, which have already been built, are coming straight down after 2012. Now that's not so sure.
Baroness Ford, who played a key role in helping to transform the Dome from a white elephant into the successful 02 Arena, said the Olympic Park must be used by both the local community and tourists every day after 2012.
She also hopes it will host a permanent Olympics exhibition.
"We have to create a real knockout destination.
"Underneath the stadium we can create a fantastic visitor attraction for Londoners and tourists - perhaps a permanent Olympic museum with good interactive attractions.
"We can have a sporting Hall of Fame.
"There are lots of organisations which want to come and locate themselves in the Park. There will be sporting, cultural and community events there.
"I think it will become a bit like Central Park in New York - beloved of New Yorkers but also a fantastic magnet for visitors to the city."
'No Dome mistake'
Baroness Ford has said she plans to carry out a full review of the stadium plans in the next five months.
The new company in charge of the legacy of 2012 is due to make a decision on the stadium's future by the end of the year.
Although the legacy company will control the Park, Baroness Ford hopes to persuade private firms to take over the running of the individual venues.
The Lea Valley Park Authority has already agreed to run the yet-to-be-built velodrome in Stratford and the white-water canoeing centre at Broxbourne in Hertfordshire.
The O2 Arena has become a major venue for music concerts
"My objective is not to go to London or the government cap in hand and say we need lots of subsidy to make all of this work," Baroness Ford added.
"I happen to think there is a clear market need for a knockout sports visitor attraction in the UK and that we will able to find the right kind of operators, as we did with the Dome."
Asked if that would be tough in a recession, she said: "If we were going looking for investors tomorrow, I would really have a problem.
"But by the time I come to commit to all of these things, four years from now, I think we expect to be in a different place."
Baroness Ford said it was crucial that Olympic chiefs did not repeat the mistakes made with the Dome at the start of the decade.
She said: "My company has three years to think about planning of events, getting the right tenants and getting the visitor attractions up and running so we are not left with a situation, as we were with the Dome, where it was empty, derelict and desolate.
"We will avoid that."
Rethink over 2012 stadium plans