G.M. bought the rights to the Hummer brand in 1999 and began making somewhat smaller Hummers. G.M. initially procured the H1 from A.M. General but discontinued the model in 2006.

Under the preliminary agreement announced on Tuesday, GM will initially continue to manufacture Hummers under contract for Sichuan Tengzhong, which will then market them around the world. G.M. will continue making the H3 and H3T models in Shreveport, La., through the end of next year, for example.

The buyer plans to shift additional production of the H3 from a plant in South Africa to Shreveport, Mr. Richards said.

Sichuan Tengzhong could bring Hummers to the crowded streets of China’s big cities, although the vehicles would face the 40 percent tax that China imposes on cars, S.U.V.s and minivans with engines over 4 liters.

G.M. has not set up its own Hummer dealer network in China, but entrepreneurs already import the vehicles and sell them in the biggest cities.

Copies of the Hummer by Chinese automakers draw crowds at auto shows, although they are labeled as concept vehicles and are not for sale.