U.S. wholesalers increased their inventories in December at the slowest pace since last summer, the government reported Tuesday in the latest sign that the economy lost some momentum at the end of 2013. The Commerce Department said wholesale businesses increased inventories by 0.3 percent in December, the smallest gain since July. Sales at the wholesale level slowed to 0.5 percent after stronger gains of 1 percent in November and 1.1 percent in October. Rising inventories support economic growth because they reflect expanding production at factories. Bigger inventories accounted for more than 40 percent of economic growth in the July-September quarter last year, when gross domestic product (GDP) increased at a strong 4.1 percent annual rate. The surge in inventories slowed in the last three months of 2013, and overall GDP growth fell back to a moderate 3.2 percent.