The two automakers signed a memorandum of understanding to start negotiations.
The Japanese newspaper Nikkei reported that the tie-up would be formalized late this month in a meeting in the United States between Isuzu President Susumu Hosoi and GM CEO Dan Akerson.
The companies have worked together on trucks in the past, which led to the development of the original Chevrolet Colorado mid-size pickup truck from GM. Isuzu sold it as the i-Series, according to Reuters.
The two companies' financial ties go back to 1971, when GM took a stake in the Japanese truck maker. In 1999, GM raised its stake to 49 percent but whittled it down over time, disappointed by Isuzu's losses and later hampered by its own financial woes.
In 2006, the two companies dissolved their equity tie-up.