More than 11,000 sq ft of office space has been let in the Mclaren building in Birmingham city centre.
Bruntwood, the family property group which owns and manages the buildings, said it was seeing a resurgence of interest in the 21-storey tower because of regeneration in the Eastside district.
The area will be home to the new HS2 station and is seeing a clutch of new investment such as Eastside City Park, expansion of the Masshouse apartment complex and a growing Birmingham City University campus.
Sigma Financial Group, a business process outsourcing provider, has taken 9,139 sq ft in Mclaren, Select Energy Group has leased 320 sq ft and incumbent tenant RFEA, the forces employment charity, has increased the amount of space it occupies by 1,100 sq ft.
Bruntwood has also recently undertaken a refurbishment of the building to bring it back in line with grade A stock in the city.
Rob Valentine, head of the firm's Birmingham office, said: "Eastside, as the home of the new HS2 station, is the focus of increasing investment from both public and private sector sources and we are expecting the recent announcement of the expansion of the Curzon Street Enterprise Zone to trigger more property speculation still.
"As we enter 2016, when high occupier demand is expected to coincide with a lack of available brand new space, we are providing a viable alternative by recycling existing space and maximising its potential.
"The Mclaren building is now 94 per cent let with space still available on the upper floors that benefit from superb, panoramic views across the city."
Originally built in the 1970s as the headquarters of HSBC, Bruntwood has invested £7.5 million in the building since it was acquired in 2008.