Control Data Corp. plans to shut down...

Control Data Corp. plans to shut down several plants temporarily and idle 7% of its work force the last week in August. The company has been faced with slower-than-expected U.S. sales of mainframe computers. The move will affect about 2,000 workers in St. Louis Park, Plymouth and Arden Hills in Minnesota and 500 employees in Sunnyvale, Calif., and Kansas City, Mo., said a spokesman for the Computer Products division, which makes mainframe computers. The move will help consolidate vacation expenses in the third quarter, which will improve cash flow in the fourth quarter, the spokesman said.