Three Rivers Pharmaceutical LLC will be relocating its headquarters from Cranberry to the Thorn Hill Industrial Park in Marshall, where it will lease 55,950 square feet in two buildings owned by the Regional Industrial Development Corp.

Paul Fagan, Three Rivers Pharmaceutical executive vice president and general counsel, said yesterday the company has outgrown its space and couldn't find more room at its current site. The new location will house the firm's offices and warehouse.

The company, which employs about 80 and could add over 20 more in the next year, plans to move by fall.

It markets, manufactures and distributes pharmaceutical drugs, mainly relating to Hepatitis C.