Chevrolet’s Kodiak and GMC’s Topkick medium-duty truck lines will be phased out by July 31 after General Motors Corp. was unable to locate a buyer for the two divisions.

According to a story Monday (June 8) in Automotive News, GM had been searching for a buyer for its medium-duty truck business ever since the divisions began losing money in 2005. A tentative deal was struck in 2007 with Navistar International, but it expired last summer without a final sale reached.

GM’s decision to jettison the money-losing business segment was apparently fueled by its bankruptcy filing last week. The company had already decided to shed its iconic Pontiac automotive division by 2010, and its Hummer division is in the midst of being sold to a Chinese manufacturer of heavy equipment machinery. A third GM nameplate, Saturn, was sold to Penske Automotive Group Inc. last week.

Although the Kodiak was a popular platform among RV manufacturers and offered owners a dependable truck-based “C-plus” motorhome with increased load-carrying capacity, sales of the Kodiak and its GMC counterpart fell off sharply in recent years. According to GM CEO Fritz Henderson, GM sold about 30,000 units in 2007, but that number dropped to just 20,000 vehicles last year as the country entered its worst recession since the 1930s.

Available in Class 5 though 7 model lines, the Kodiak and Topkick are built in five models, with GVWRs ranging from 16,500 to 63,000 pounds.