The firm is understood to have pipped rival Skanska to the high profile £100m fit-out and rebuild job.
A source told the Enquirer: “Byrne’s are down on site talking to the client so it looks like they have come out top, although for a while it looked like the job was going Skanska’s way.”
The overhaul programme will see 13 floors of current office space converted to provide a 360-bedroom hotel.
Developer Archlane also has permission to create a new roof extension from the 12th floor to provide a new bar for the hotel’s use.
The redevelopment includes extensive work to overhaul the facade of the building, which will retain its characteristic golden globes and signage.
Plans also include construction of a nine-storey extension to the rear of Sea Containers House to provide retail at ground floor level and offices above.
The Thames-side building was originally conceived as a luxury hotel but was reconfigured as offices before it opened in 1978. It is named after its original owner, an international shipping company.
Chorus was main contractor on the recent renovation of the Savoy hotel.