FLINT, MI – Navistar apparently is very serious about buying General Motors’ medium-duty commercial truck business, which is based at GM’s Flint Truck Assembly Plant, according to the Flint Journal. In a call for analysts, several pages in a 104-page report detailed why Navistar, maker of International-branded trucks, was interested in buying GM’s North American commercial truck operation.

Under a section labeled “Leveraging what we have and what others have built,” Navistar indicated it might buy into GM’s medium-duty business for about $100 million, and turn up new revenue in the $1.5-billion range. Navistar said taking over GM’s design, manufacturing, and distribution channels would lower labor costs and reduce production time.

GM has not spoken about a deal, and insiders say both sides are far from final numbers, according to the Flint Journal.

GM built more than 36,000 medium duties in 2006, a small segment of the overall automotive market. They are almost custom-built on a separate line at Flint Truck. A second line builds GM’s profitable heavy-duty crew cab pickups for Chevrolet and GMC.