General Motors to unveil Hummer H4 concept in Detroit

GM will use January's Detroit auto show to unveil a Hummer H4 concept, according to sources cited by Automotive News. The small truck would be designed to compete with the Jeep Wrangler, the report said. A production model would likely arrive for the 2010 model year.

In June, rumors began circulating that General Motors might dump the Chevrolet TrailBlazer and effectively replace it with a new Hummer model called the H4. Currently, the brand has two models: the H3 and the H2. The large H1 was discontinued this summer.

General Motors has said it's interested in expanding the Hummer line by two or three models. As confirmed by recent spy photos, the automaker is also believed to be developing a pickup truck based on the Hummer H3.