Control Data said it plans to close a plant.

Blaming weak demand for computer disk drives, the Minneapolis computer firm said it will also close 16 other plants for two weeks in July. The plants are owned by Magnetic Peripherals, a joint venture with Honeywell, Sperry and the Bull Group of France. The plant in Burnsville, Minn., being permanently closed employs 450 and makes memory devices. The company said other closings are possible as it carries out previously announced consolidations. Control Data lost $9.2 million in its latest quarter.