General Motors Corp. says it plans to build a new assembly plant in San Luis Potosi, Mexico.

The auto maker, under financial duress in the U.S., where it has earmarked several plants for closing and is idling both hourly and salaried workers, kept the announcement low-keyed and is offering few details.

Reports out of Mexico suggest the plant will build compact vehicles beginning in 2008. Employment is expected to total about 1,800 people and initial production will be set at 30 vehicles per hour.

Investment is pegged at $600 million to $650 million, press reports say. Construction is to begin in May.