The property is located on the Thames’ South Bank, next to the Tate Modern.
The new events space is located on the tenth floor and will offer a landscaped roof garden for 250 delegates and nine meeting rooms, the largest of which has capacity for 40.
Event space will also include a lecture theatre for 96 and a wine-tasting room.
Blue Fin Building facilities director Jenny Noon said: "A hub where many social, philanthropic and community initiatives were pioneered, Southwark is the perfect location to play host to corporate and consumer entertaining."
Sodexo Prestige will provide the venue’s all-inclusive event-management service.
The Blue Fin Venue will be available for hire from 11 November.