With the departure of Interserve, Interserve Prime now becomes Prime Partnering Solutions Ltd but otherwise continues unchanged.
Interserve remains, a key supply chain partner to Prime and the two companies continue to enjoy a good working relationship, they said.
"The acquisition will 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," the company said.
Interserve has not yet disclosed what impact the deal will have on its ailing finances and its share price remained below 13 pence on the news.
Prime works across the health and care system, delivering projects through strategic estates partnerships (SEPs) for the past four years. SEPs are 50-50 joint venture companies operated between the public and private sector.