Property Group, Great Portland Estates (GPE), has joined with Ropemaker Properties Limited in a new development, it has been reported.
Its site at 240 Blackfriars Road could feature an 18-storey office retail and residential scheme, under new proposals for its development.
GPE boss Tory Courtauld said the deal "allows us to spread our development risk at Blackfriars Road and it forges a new relationship with a high quality partner opening up new avenues for future business together".
The Great Ropemaker Partnership JV bought the site for an initial consideration of £20.5 million after the previous buildings at the junction of Blackfriars Road and Southwark Street were demolished.
The planned mixed-use scheme would create 207,000 sq ft of space, which could be let as new offices in London.