Craigavon-based pharmaceutical giant Almac has officially gained full possession of both buildings in its two-part North American headquarters project.
The use and occupancy permits confirm that the building rights, previously shared with construction partner Skanska, are now solely under Almac's ownership.
The $120m (£77.6m) scheme, which began in summer 2008, is nearing completion as employees prepare for an early autumn move.
Relocation will begin this month, with the official grand opening of the headquarters planned for late spring next year.
Almac chief executive Alan Armstrong said the company was excited to see the next phase of the project finished.
"The completion of our new North America headquarters facility will support our continuing business growth, and better enable the fulfilment of Almac's mission to advance human health by bringing new drugs to market sooner," he said.
Almac chairman and founder Sir Allen McClay, recognised as one of Northern Ireland's leading entrepreneurs, died in January. He began the company in 2000, buying five divisions from his former company Galen in order to keep jobs in Northern Ireland.
Sir Allen began his career as a pharmacist.
The company has over 2,500 employees across Northern Ireland, the rest of the EU, and the United States.