The incredible shrinking Control Data Systems Inc, now primarily a systems integrator, is to sell its 50% stake in Metaphase Technology Inc and some assets of its product data management business to its partner in the effort, Structural Dynamics Research Corp, for about $31m in cash and a warrent for Structural Dynamics shares. The sale will produce a gain for Control Data, and be accounted for as a purchase by Structural Dynamics. The other assets include the Arden Hills, Minnesota company’s global product data management software sales and support business, and its North American and European customer base. Control Data also agreed not to compete in product data management software for two years, and will become a systems integrator for Metaphase and Structural Dynamics, of Milford, Ohio. Structural Dynmaics expects to take a $25m one-time charge in its first quarter 1997.