Enterprise House in Paddington has recently been sold by Helical Bar.
The sale price was in the region of £43m; this would equate to a net initial yield of 4.04%.
The purchaser reportedly was a private overseas buyer.
Enterprise House is currently the London headquarters for Network Rail and comprises of 45,000 sq ft of office space.
The property was comprehensively refurbished in 2013 by Network Rail.