The £20m job has lured in London specialists Mace, Kier Wallis, ISG, Overbury and Mansell.
A decision on the winning bidder for the 100,000 sq ft refurb is expected early next year to allow staff to move into the offices before the end of 2012.
The location of the office building has still to be announced and will become home of the Bank of England’s new financial regulator, the Prudential Regulation Authority.
This will be created once the government completes its proposed break-up of the Financial Services Authority.
The offices will be bought as a shell and need to be completely re-fitted to make them fit for purpose.