ST. LOUIS — Hilliker Corp. has arranged the sale of two industrial buildings in St. Louis for approximately $7 million. Serioplast, a plastic manufacturer based in Italy, purchased a 132,000-square-foot building located at 4400 Planned Industrial Drive. Service Metals Inc., an industrial valve distributor, purchased the property located at 4300 Planned Industrial Drive. Madison Warehouses built both properties in the 1990s. Hal Ball and Chris Taff of Hilliker Corp. represented the tenants in the transactions.