Toyota Motor Corp. told U.S. dealers that assembly disruptions triggered by last month's record earthquake and tsunami in the Tohoku region may thin supplies of vehicles into the third quarter.

The world's largest automaker will build vehicles at "significantly reduced levels," Bob Carter, group vice president of U.S. sales, said in a memorandum to dealers. While Toyota, Honda Motor Co. and Nissan Motor Co. reported mostly minor damage at domestic plants from the March 11 disaster, all three cut output in Japan and abroad as they rebuild stockpiles of parts from suppliers whose operations were disrupted.

Toyota, which estimates that North America generates about 60 percent of its operating profit, said last week it would suspend production at auto, engine and parts plants in the region for five days this month because of a shortage of Japan-made components. The company plans to restart all plants in Japan by April 18 at half of their capacity, it said last week.