The Mexican unit of General Motors Corp. (GM) will idle its plant in the central city of Silao for one week beginning Monday following a decline in demand for vans, a company spokeswoman said.

Teresa Cid said the stoppage is scheduled to last one week, with production set to resume on April 27.

The Silao plant, which makes the Chevrolet Avalanche, Cadillac Escalade and several models of extended-cab pickup trucks, is one of four production plants that the auto maker operates in Mexico.

Mexican auto makers have been carrying out a number of work stoppages this year as domestic and export demand falters.

The country's auto production fell 41% in the first quarter, with exports down 41% from the first quarter of 2008 and domestic new car sales off 26%.

Shares of GM traded recently at $1.72, down 14 cents, or 7.5%.

-By Anthony Harrup, Dow Jones Newswires; (5255) 5001-5727, anthony.harrup@dowjones.com