General Motors is back in the medium-duty commercial truck market with a just-announced long-term agreement with Navistar.

The deal, which will see conventional cab Class 4/5 commercial vehicles hitting the market in 2018, allows Navistar to strengthen its product lineup and GM to expand its Chevrolet commercial truck portfolio.

GM offered medium-duty trucks for decades before getting out of the business in 2009 in the midst of its bankruptcy reorganization and the recession. That decision followed the death of a deal for Navistar to buy GM's medium-duty business.

"Bringing medium-duty conventional cab trucks back into the portfolio strengthens Chevrolet's commitment to providing commercial customers with more choices and one-stop shopping for a versatile lineup of trucks, vans and crossovers," said Ed Peper, U.S. vice president of GM Fleet and Commercial Sales.

The future products will be jointly developed using Navistar's expertise in rolling chassis configurations and manufacturing capabilities, and GM's commercial components and engines. The vehicles will be manufactured at Navistar's facility in Springfield, Ohio. Navistar plans to add 300 jobs and invest more than $12 million in facility upgrades and equipment to produce the new vehicles.

"Our collaboration with GM is another example of our customer-centric, open integration approach — providing our customers with the best technologies available," said Bill Kozek, president, Truck and Parts, Navistar. "By working with an industry-leading company like GM, we'll be able to enhance our medium-duty product portfolio and leverage our scale and expertise in manufacturing medium-duty trucks."

Specific terms of the agreement were not disclosed. Additional product information will be announced later.

This news follows GM's June announcement that it's getting back into the low-cab-forward market through a deal with Isuzu.

Navistar for years built medium-duty trucks for Ford through the Blue Diamond venture, which ended last year. Ford began production of its own F-650 and F-750 this year at its Ohio plant.