Construction information specialist Glenigan has confirmed that the contractor has secured the job after taking the basement and substructure package several months ago.
The builder beat rival bids from Bam Construct and Sir Robert McAlpine to take the 210,000 sq ft office development.
Private developer Favermead was forced to put the project on hold in 2007, but dusted off the plans which were drawn up by architect Kohn Pedersen Fox a year ago when the London office market started to stir.
Since then Axa Insurance was brought on board to jointly develop the office.
A key component of the redevelopment of 60 Holborn Viaduct is the rebuilding, in traditional materials, of the Gate House at the north east corner of the Farringdon Road – Holborn Viaduct junction.
The new Gate House will complete the existing set of three structures that were originally erected as a grand gesture during Victorian times.