Jan. 4 (Bloomberg) -- Nissan Motor Co. fell the most in more than six years on the Tokyo Stock Exchange, leading Japanese automakers lower after Toyota Motor Corp. cut its forecast for U.S. sales and the yen rose against the dollar.

Nissan, Japan's third-largest carmaker, plunged 9.2 percent to 1,117 yen as of the 11 a.m. close of trading in Tokyo. Toyota, the country's biggest automaker, fell 4.3 percent to the lowest in 17 months, while No. 2 Honda Motor Co. fell 4 percent.

Toyota and Nissan's U.S. sales fell in December as a drop in manufacturing showed economic growth is slowing. The companies get as much as 65 percent of their operating profit in North America. Toyota trimmed its 2008 forecast for U.S. sales growth yesterday, to a range of 1 percent to 2 percent, from an earlier prediction of 3 percent.

``December auto sales figures in the U.S. announced yesterday are contributing to the sell-off, as well as currency movements,'' said Mutsuo Nakano, an auto analyst at investment research company Morningstar Inc. in Tokyo. ``The car sales outlook for the U.S. looks difficult.''

The yen traded at 109.10 against the U.S. currency as of 12:15 p.m. in Tokyo, after touching 108.25 yesterday, the strongest since Nov. 27. A rising yen against the dollar cuts the value of automakers' U.S. sales.

Mazda Motor Corp., which exports 80 percent of domestic production, fell 7.7 percent to 515 yen.

U.S. Sales

Auto-related shares were the third-biggest contributor to a 4.3 percent drop in the Topix index of all shares on the Tokyo exchange's first section. The market closed after the morning session.

U.S. sales at Toyota and Nissan declined last month as year-end gasoline prices in the U.S. topped $3 a gallon for the first time. Housing starts, a barometer for sales of pickup trucks, are in the deepest slump in 16 years.

The Institute for Supply Management's manufacturing gauge declined to 47.7 in December, the group said on Jan. 2, more than economists had forecast.

Toyota reported a 1.7 percent sales drop in December as demand for its top-selling models such as the Yaris and Corolla small cars and the Camry sedan declined, the Toyota City-based company said yesterday. The automaker expects to sell 2.64 million cars and light trucks in the U.S. this year, it said on Dec. 25.

Honda sold 131,792 vehicles in the U.S. last month, little changed from 131,778 a year earlier, the company said. The Tokyo-based automaker said on Dec. 19 it expected to raise U.S. sales by 3 percent to 1.59 million units in 2008.

Nissan sold 89,555 vehicles, a 2.4 percent drop from December 2006, according to the company.

Isuzu Motors Ltd., Japan's largest maker of light-duty trucks, sold 492 pickups and SUVs in the U.S. last month, down 23 percent. The shares fell 7.5 percent in Tokyo, the most in more than four months.

Overall auto sales in the U.S. fell 2.9 percent in December to 1.39 million, and the full-year total declined 2.5 percent.

To contact the reporter on this story: Naoko Fujimura in Tokyo at nfujimura@bloomberg.net

Last Updated: January 3, 2008 22:53 EST