CBRE and WHR have been appointed to seek offers for the 142,000 sq ft 100 Barbirolli Square in Manchester.
Moorfield Group and Oaktree Capital are selling the block with an asking price of £52m, having purchased it in 2013 for £41m.
Law firm Addleshaw Goddard and accountancy EY will vacate the block in 2016.
It follows the £32m sale of 101 Barbirolli Square to AEW Europe.
