Knight Frank has been appointed as joint agents alongside CB Richard Ellis to market the Port of Liverpool Building on behalf of owner Downing.
Downing is currently progressing the refurbishment of the 155,000 sq ft Grade II*-listed landmark within Liverpool's World Heritage site.
The £10m scheme will deliver new office suites alongside a restoration of the 1907 building's interior and exterior using original materials.
Around 31,982 sq ft of commercial space is available to let at the building, in suites from 600 sq ft upwards.
Graham Bowling, partner at Knight Frank, commented: "Downing's ongoing programme of refurbishment and improvement has ensured that this iconic building has retained its position as a headline address for quality covenants. These improvements consistently add to the enhancement of the waterfront location as an increasingly active location within the city."
Robin Ellis, senior agency surveyor at Downing, said: "We're investing heavily to complement the Port of Liverpool Building's architecture and location with modern office space that meets the exacting standards of high quality occupiers. By future-proofing the building, we're not only ensuring it will be enjoyed by future generations, but that tenants can be assured of competitive service charges and no interruptions."
This year has seen 20,000 sq ft of refurbished space let at the building to blue chip firms including DHL Global Forwarding and Hapag-Lloyd.