The property is owned in a 25:75 joint venture with the state of Oman, who purchased their 75% share from Hammerson last year for £445m.
The building, which comprises 850,356 sq ft of office space in the City of London and an additional 49,514 sq ft of retail space, was completed by Hammerson in 2005.
The E1 office space is currently fully let to city law firm Allen & Overy.
According to Property Week, David Atkins, chief executive of Hammerson, said “This disposal fits with our strategy of creating value through portfolio management. We retained a stake in Bishops Square after the sale to Oman Investment Fund and have worked well together on the joint venture."
He added: "We are capitalising on the market recovery over the last 15 months and Hammerson has released funds for investment into other office and retail developments and acquisitions.”