GM says will shut five U.S. plants in January to adjust supply

General Motors Co will shut five U.S. auto assembly plants for varying durations in January, primarily to cut oversupply of sedans which have fallen out of favor among U.S. consumers. GM confirmed on Monday information from sources at the United Auto Workers union who said that the five plants will shut. GM had built up inventory recently and will be cutting back on that supply after the end of the current year.