The post-games organising body also gained approval to create a community hub in the north of Park, where plans are more advanced for opening in 2013.
Tenders have already been invited to find a contractor to deliver the design and build contract for the hub and visitor centre.
The creation of the Queen Elizabeth Olympic Park is predicted to be one of Europe’s biggest projects of its kind.
Bam Nuttall and Mace will play pivitol roles in delivering much of relandscaping and transformation.
Mace is overseeing the work as project manager with Bam, operating under a £49m contract for the north of the park and £27m price for the south.
The £20m South Plaza scheme will cover a 28-acre space between the Aquatics Centre, the stadium and the ArcelorMittal Orbit sculpture.
Designed by James Corner Field Operation, the landscape architects responsible for the award-winning High Line in New York, the South Plaza comprises a series of outdoor “rooms”.
The London Legacy Development Corporation said the South Plaza would be “a place to stroll and people-watch”, to contrast with the greener North Park and its lawns, wetlands and canal paths.