Fairchild Semiconductor Corp., based in South Portland, will shut down most of its U.S. operations during Thanksgiving week.

Company officials blamed the temporary closing on the troubled economy and drop in demand for Fairchild's power management chips used in consumer appliances and electronic devices.

Company spokeswoman Patti Olson said all of the office workers and many of the manufacturing staff will be off that week. But if business orders permit, some of the manufacturing staff will continue to work that week.

Fairchild employs about 1,000 workers at its offices on Running Hill Road and manufacturing plant on Western Avenue. Most of the 1,000 workers Fairchild employs at its other U.S. locations will also be off that week.

There have been companywide shutdowns at Fairchild in the past, most recently during the dot-com meltdown in 2001.