The law firm has bought 55 Spring Gardens in Manchester for £8.5m, reflecting a net initial yield of 9%.
Linder Myers, currently based at Phoenix House on Cross Street in the city centre, will use the eight-storey building as its new headquarters.
The property comprises 47,500 sq ft of office space and is let to tenants including financial services group Friends Provident and CB Richard Ellis and includes vacant retail space on the ground floor.
Hermes Real Estate Investment Managers held the property on behalf of British Telecom's pension scheme.
Berkeley Brown acted on behalf of Linder Myers, while BTPS was represented by WHR Property Consultants.
Legal advice was also provided by Hill Dickinson.