TORONTO - Toyota is extending plant shutdowns in Canada and the United States as a result of part shortages following the devastating March 11 earthquake and tsunami in Japan.

In its latest announcement, the company said production at plants in Woodstock and Cambridge, Ont., will be suspended the week of May 23 in conjunction with the Victoria Day weekend.

U.S. production will be suspended the week of May 30 in conjunction with the scheduled Memorial Day holiday.

"No layoffs are planned during this period," said a release issued by Toyota Motor Engineering & Manufacturing North America Inc. or TEMA. "Team members will utilize non-production time for training and plant improvement activities."

Toyota has three assembly plants in southern Ontario, including a Corolla/Matrix plant and a Lexus plant in Cambridge, and a RAV4 plant in Woodstock. Together they employ about 6,500 people.

Previously, TEMA had announced production suspensions on Mondays and Fridays from April 15 through April 25. That will now continue from April 26 through June 3, with production running at 50 per cent on Tuesday, Wednesday and Thursday during the period.

"TEMA is trying to continue production as much as possible with its workforce intact in order to facilitate a smooth transition back to full production when all parts are available," the company said.