Clive House was sold by Land Securities to German fund manager Real IS, PropertyWeek has reported.
The building is currently let to the Department for Constitutional Affairs, which pays rent of £34/sq ft.
The deal is part of Land Securities’ sale of its non-core assets that netted the firm less than expected, the commercial propertywebsite has suggested.
It claimed it was hoping to get £81 million, a four per cent yield, when it bought the building to the market in December 2007.
Real IS is also buying 14 Tothill Street, a 56,000 sq ft office near Parliament Square for £58 million from Gracemark.
Land Securities is set to de-merge. Rick Haythornthwaite, the new chairman of its retail arm, told the Telegraph: "It clearly has a high-quality estate which it is managing for value very well, and it is going to be in a very strong position."