AutoNation Inc., the largest U.S. car retailer, said the restocking of dealer lots with new vehicles from Japanese manufacturers will boost demand while lowering profit margins through the end of the year.

AutoNation will take delivery of more than 30,000 vehicles in the fourth quarter from Japan-based automakers, including Toyota Motor Corp. and Honda Motor Co., said Michael Maroone, AutoNation's president and chief operating officer. Those automakers shipped fewer than 20,000 new cars and trucks in the third quarter, Maroone said Thursday.

Chief Executive Officer Mike Jackson boosted prices after the March quake and tsunami led to car shortages and helped push the seasonally adjusted annual rate of U.S. auto sales below 12 million in May and June.