Business inventories in the U.S. rose a slight 0.1% in December after a 0.2% decline in the prior month, the Commerce Department said Friday. The gain was in line with Wall Street expectations. Sales slumped 0.1% in the month. Retailer sales were flat. The ratio of inventories to sales, meanwhile, inched up to 1.40 in December from 1.39 in the prior month. That's how many months it would take to sell all the inventory on hand. One year ago, the inventory-to-sales ratio was 1.39. A smaller gain in inventories in the fourth-quarter relative to the July-September period subtracted 1.1 percentage points from GDP growth.