BIRMINGHAM - Almost 200,000 U.S. customers looking to buy new vehicles are "up for grabs" because of parts shortages caused by the March 11 earthquake and tsunami in Japan, according to a new report.

The major Japanese automakers - Toyota Motor Corp, Honda Motor Co Ltd and Nissan Motor Co Ltd - are at risk for the biggest lost sales, according to the A.T. Kearney report, which was released on Tuesday, reported Reuters.

U.S. automakers General Motors Co, Ford Motor Co and Chrysler Group LLC as well as South Korea's Hyundai Motor Co stand to capture most of the consumers who defect from the Japanese brands, said Dan Cheng, head of A.T. Kearney's American automotive practice.

Of the estimated 1.66 million units of lost production globally because of the Japan crisis, 341,000 would have been sold in the United States this year. Of those lost U.S. sales, 42 percent were buyers who likely will remain loyal to their current brands, said Cheng.

Of the remaining 197,000, an estimated 80 percent were with Toyota, Honda and Nissan, A.T. Kearney said. Another 36,000 are with other Japanese manufacturers.

If full production at Japanese plants does not resume until the fourth quarter, the number of new vehicle sales up for grabs will rise to 328,000, or the equivalent of 2-1/2 points of market share, Cheng said. Of those, 263,000 would be with Toyota, Honda and Nissan.

A.T. Kearney also expects U.S. new-vehicle sales to grow almost 14 percent to 13.2 million this year from 11.6 million in 2010, and reach 16 million in 2013 as consumers replace an aging fleet of vehicles. After that, growth will rise more slowly, hitting 16.7 million in 2016.

In the decade before the 2008-2009 industry downturn, U.S. auto sales averaged nearly 17 million in new vehicle sales a year.

Since the beginning of the recession, new- and used-vehicle U.S. sales combined have fallen 15 percent to 48 million units, the lowest level since 1983, mostly because of lower availability of vehicle financing, according to A.T. Kearney. A bounceback in financing will help projected future growth.

A.T. Kearney said increasing loan approval rates for buyers with subprime, or very low, credit scores, to an average of 40 percent from the below 20 percent rate where it is now would yield an additional 800,000 new-vehicle sales.

Based on stricter loan approval rates, 530,000 newly rated subprime buyers will be shut out of the 2011 U.S. new light-vehicle market, A.T. Kearney said. That represents a $3.2 billion contribution margin opportunity for automakers.