Isuzu Motors Ltd., the nation's largest maker of light-duty trucks, said Wednesday it cut its full-year profit forecast as sales slow in Thailand and a stronger yen reduces overseas earnings.

Net income may fall 47 percent to ¥40 billion in the year ending next March, from ¥76 billion a year earlier, the Tokyo-based company said in a statement. Isuzu previously forecast profit of ¥85 billion.

Isuzu's truck sales in Thailand, its biggest overseas market, have dropped for four straight months through September as rising economic concerns dampen demand. Steel prices, which reached a record in mid-July, and a stronger yen are also eroding the value of the truck maker's overseas sales.

"Raw materials costs and the currency are certainly having a negative impact," said Chikashi Okabe, a Tokyo-based analyst at Credit Suisse Ltd., who has an "outperform" rating on Isuzu. "A slowdown in Thailand and Europe also looks worrisome."

Fiscal second-quarter net income fell 22 percent to ¥12.38 billion and sales dropped 5.9 percent to ¥444.5 billion, according to Bloomberg calculations. Second-quarter figures were derived from first-half results released by the firm Wednesday.

Isuzu commands about 40 percent of the light-truck market in Thailand, where the segment accounts for 60 percent of total auto sales, according to Macquarie Securities Ltd.

The company earned 30 percent of operating income in the Southeast Asia region last fiscal year, most of which came from Thailand, according to Tadashi Ioka, a spokesman.