Price cuts at Nissan and strong demand for pickup trucks helped U.S. auto sales rebound in May after a slight dip in April. General Motors (GM) reported Monday its strongest monthly sales since September 2008. Chrysler, Ford, and Toyota also reported increases. Nissan notched its highest May sales ever after cutting prices on seven popular models early in the month. Only Volkswagen said sales fell compared with May of last year. The strong sales provide another sign that auto sales will continue to boost the U.S. economy, as American consumers replace aging vehicles and businesses invest in trucks while they gain confidence. Builders are buying pickup trucks at a rapid pace, as home construction continues to rebound. Ford said that sales of its F-Series pickup - the best-selling vehicle in the United States - hit 71,604, their highest sales since March 2007. Chrysler said that Ram pickup sales jumped 22 percent from last May to almost 32,000. Chevy said that its Silverado sales rose 25 percent to more than 43,000. Analysts expected a strong May for the industry after a slightly disappointed April. They forecast a 7 percent increase over May 2012 to roughly 1.4 million vehicles, putting the industry back on pace for full-year sales of more than 15 million. In April, the annualized rate dropped below 15 million for the first time in six months, causing some concern that the industry's recovery could be slowing.