Relatively mild weather this winter season is being blamed for the layoff of about 80 people at the Sifto Canada Corp. mine in Goderich, Ont., a major producer of highway de-icing salt.

Communications manager Kelly Barton said Friday that several factors, including the weather and a lack of storage, forced the layoffs, which represent about a fifth of the mine’s work force.

Sifto also is reducing its operations from seven days a week to five, the company said.

Ms. Barton said the layoffs were temporary and that most of the employees would be called back in the second quarter of the year.

The Sifto mine employs about 400 people and produces road and highway de-icing salt for customers in the Great Lakes region.

Sifto and its U.S. parent are spending $70-million to expand the Goderich mine, already the world’s largest underground rock salt mine, to meet growing demand. The upgrade will increase annual production capacity to about nine million tons by 2012.

Sifto is a wholly owned unit of Compass Minerals International Inc. CMP-N

, a company based in the Kansas City area.

The U.S. company, which employs more than 1,700 workers, also operates rock salt mines in Cote Blanche in Louisiana, and in Cheshire in the United Kingdom.