Local architects practice Hodder and Partners first drew up redevelopment proposals last year but the scheme was put on hold.
Now the plans have been dusted down to take advantage of swelling office and hotel demand in Manchester.
The developer aims to convert the old Richard Seifert-designed curved office building into a 270 bedroom hotel, with shops on the ground level.
The project also includes a new-build 40,000 sq ft office block and more than 8,000 sq ft of retail space facing Ducie Street.