Lake Forest, IL, June 4, 2001 – Packaging Corporation of America (NYSE: PKG) has today announced the purchase of Sunbelt Packaging Service, Inc., a privately-held corrugated box manufacturer in Tucson, Arizona.  Terms were not disclosed. Sunbelt's operations will be incorporated into PCA's Western Area, which currently operates plants in California, Utah, Texas and Arizona.  Sunbelt employs approximately 65 people at its Tucson facility and also has a distribution and service center in Nogales, Mexico.  William J. Sweeney, Executive Vice President, Corrugated Products, noted "The acquisition is a good fit with our existing plants and will also strengthen PCA's position along the Mexican border."   The transaction was completed June 1, 2001. With net sales of $1.9 billion, PCA is the sixth largest producer of containerboard and corrugated packaging products in the United States. Corrugated packaging products include conventional shipping containers, multi-color boxes, and retail merchandising displays.  PCA's corrugated products manufacturing facilities will now include 66 plants and five graphic design centers, strategically located throughout the United States.