The layoffs are permanent, Bennett added. "These are role reductions. They are separating permanently from the company."
The layoffs were across the ranks of the mine's salaried workforce and are effective immediately. "This is not one specific group or department," Bennett said, noting that workers would receive severance packages.
"These are very hard decisions for us. When you deal with people it's always harder because it impacts them, their lives and their families," he said.
A still-undetermined number of hourly employees will lose their jobs later this month or in June because of the collapse of the northeast section of the 4,000-foot-deep open pit mine.
Mine officials have said the collapse will cut expected ore production in half in 2013.
On another employment front, at least 150 people have expressed interest in a $20,000 early retirement bonus that Kennecott put before 275 qualified hourly workers earlier this month, said Wayne Holland, international staff representative for the United Steelworkers of America.
"Of that  number, I would expect a fairly high percentage will actually take the offer and decide to retire," Holland said.
The qualified workers have until June 1 to decide.
Holland is the spokesman for 1,800 workers who are represented by four unions at the mine. He said he doesn't know yet when Kennecott will announce layoffs of hourly workers.
"It's a painful experience, and it's difficult because in the past we've been able to see [layoffs] coming because of bad markets and copper prices being very low. This time,it's a seismic event that caused things we couldn't control, and it's out of the blue. So the impact is more deeply felt," he said.