Hochtief subsidiary John Holland will be responsible for the excavation and construction of the new underground loading dock and upgrade of the forecourt roadway, with work starting in January 2012.
This contract, with an approximate value of just over AU$100m (£64m), is part of the AU$152m upgrade of Sydney Opera House and is the biggest building scheme on the site since its opening in October 1973.
The project involves excavation and construction of a new access road and loading dock under the forecourt and vehicle concourse as well as raising of the existing road to remove the kerbs.
John Holland group managing director Glenn Palin said: "We are honoured to have been selected to deliver these vital upgrade works, which will improve accessibility and amenity for local and international visitors to this iconic Australian structure. The contract highlights both our reputation for the delivery of high end building solutions and the strength of our tunnelling expertise."