Matrix Court in Swansea had been bought by Colony Capital.
The sale price for the 28,182 sq ft of office space was £2.35m. This reflects a net initial yield of 11.35%.
Matrix Court comprises two separate buildings; Tyr Llyn and Venture Court.
The current tenants in the building are JCP Solicitors and the Welsh Government.
Colony Capital also owns the adjoin building, which they purchased in 2013.