Prime has acquired full shares in Interserve Prime and rebranded the business Prime Partnering Solutions.
The business is currently working in three strategic estates partnerships with NHS Foundation Trust at University Hospital Southampton, Yeovil District Hospital and Dorset County Hospital.
Prime said that the acquisition would have no impact on ongoing projects other than to offer increased efficiency and the convenience of a single point of contact to clients and suppliers.
Interserve said that it would remain a supply chain partner to Prime and that the two companies continued to enjoy a good working relationship.
Prime works across the health and care system and has more recently become a leading partner for the acute sector, delivering projects through Strategic Estates Partnerships.
These 50-50 joint venture companies operated between the public and private sector deliver a broad range of projects and services to public sector clients, from developing new clinical and commercial real estate through to facilities management and consultancy services.