"In June 1961, the Pacific Car and Foundry Company (which is no longer involved in defence) was awarded an initial production contract for both the M107 and the M110. First production vehicles were completed in 1962 and the first M110 battalion was formed at Fort Sill early in 1963. Production of the M110 was also undertaken at a later date by the FMC Corporation of San José and Bowen-McLaughlin-York (BMY) of York, Pennsylvania. Both these companies merged to become United Defense LP. Today, the latter company is called BAE Systems, Ground Systems. Original production of the M110 was completed in the late 1960s, by which time about 750 vehicles had been produced. In FY78, 209 M110A2s were ordered at a cost of USD109.3 million for delivery from 1979."
Source: http://www.army-guide.com/eng/product1778.html