A local manufacturing company has been sold. GC Inc. has announced the sale of its Abingdon and Church Hill glass plants.The company says it reached an agreement to sell its North American architectural glass business to Cardinal Glass Industries for $450 million. In addition to the Church Hill and Abingdon plants, the deal also includes the sale of a third plant in Kansas.Pending the approval of regulators, AGC expects to close the deal in July. Noone is sure how the three manufacturing sites will be impacted by the sale.