Isuzu Motors Ltd., Japan's largest maker of trucks, said Tuesday it's considering forming business alliances with companies including General Motors Co.

"Isuzu is considering possible alliances with not only GM, but with other companies," the truck maker said in a statement to the Tokyo Stock Exchange, without specifying details. "No decision has been made."

GM may buy a 10 percent stake in Isuzu and start joint development of commercial vehicles for Southeast Asia and Central and South America, the Nikkei newspaper reported Sunday, without saying where it got the information. Such a purchase would make the U.S. carmaker the biggest shareholder in Tokyo-based Isuzu.

Isuzu rose 1.5 percent to ¥466 at 10:55 a.m. in Tokyo trading. The benchmark Nikkei 225 stock average declined 1 percent.

GM spokesman Greg Martin said Sunday the company "routinely" speaks to other companies.

GM, which held shares in Isuzu previously, sold a 7.9 percent stake in 2006. Mitsubishi Corp. owns 9.2 percent of Isuzu and Toyota Motor Corp. owns 5.9 percent, according to data compiled by Bloomberg.