Great Portland Estates is close to sealing two acquisitions that could pave the way for a 600,000 sq ft prime City of London office scheme.

Property Week understands that the property company has this week agreed to pay £95m for the long leasehold interest in the 180,000 sq ft City Place House, 55 Basinghall Street, to European property fund manager AEW Europe. GM Real Estate advised AEW.

At the same time, Great Portland has announced the formation of a joint venture with the long-leashold owner of the adjacent 100,000 sq ft City Tower, US group Starwood.

The new joint venture, The Great Star Partnership, will own the long-leaseholf valued at £35m. The freehold of both properties is owned by the City of London Corporation.

Architect Eric Parry has designed a 600,000 sq ft office scheme for both the City Place House and City sites, which sit between Moorgate and Bank in the City.

The acquisitions are the latest in a push by Great Portland into the City from its core West End base. Last month it signed a 50/50 joint venture with Canadian fund manager Brookfield to build a 40-storey, 770,000 sq ft tower at 100 Bishopgate.