MOUNT HOLLY SPRINGS, Pa., OCT. 4 -- The final project in Corning Inc.'s $1 billion campaign to expand its worldwide manufacturing capacity during 2000 will be an operations facility for the company's Frequency Control unit. The 40,000 square foot facility is currently under construction at Corning Frequency Control Inc.'s headquarters in Mount Holly Springs, Pa. The new building will contain a state of the art engineering center, allowing concurrent engineering complete with environmentally controlled labs for design and testing of new prototypes, said Howard Zingler, a Corning division vice president.Corning Frequency Control designs and manufactures precision crystal oscillators, resonators, and filters that serve as stable frequency references for a broad range of wireless and wireline communications technologies.