Developers Deeley Freed Estates have been chosen as the preferred partners for a £150m development based in Bristol's city centre.
The development will transform part of the Castle Park area
The St Mary le Port site covers the historic Castle Green area.
Landowners Bristol City Council, Morley Fund Management and Strand Street Properties will now work with the firm on a planning application.
If successful, work to create the multi-million pound development will start in 2007.
The scheme will be a mix of offices and residential with retail and leisure outlets.
The proposals from Deeley Freed also includes a landmark office building next to Bristol Bridge.
The scheme will now face a review period and a detailed public consultation.