General Motors Co., saddled with large stocks of unsold cars and trucks, is taking steps to cut excess production and signaled there may be more to come, the Wall Street Journal reported today. Workers at its Lordstown, Ohio, assembly plant soon will be off the job for three weeks instead of a planned two-week Christmas shutdown as the Detroit auto maker curtails Chevrolet Cruze output. The company also said yesterday that year-end inventories of Silverado and Sierra pickups may exceed 220,000 vehicles in part due to a decision to hold the line on discounts. The higher-than-expected supply will likely push GM's overall car and truck inventory beyond a year-end target of 670,000 vehicles.