CANTON (AP) — Nissan will invest $118 million to retool a Mississippi auto plant to produce a new commercial vehicle — the first production of its kind for Nissan in the United States.

Dan Bednarzyk, vice president of manufacturing at Nissan in Canton, said Wednesday that modifications at the plant have begun and production will start in 2010.

Bednarzyk said Japan’s third largest automaker, which last month announced 20,000 job cuts globally amid an industrywide downturn, reached the decision after seeing commercial vehicle sales grow by 8 percent in overseas markets.

Nissan’s concept commercial vehicle was being unveiled Wednesday at a national truck show in Chicago, he said.

‘‘In light of the current (economic) condition globally we are really excited about what is going on here today,’’ Bednarzyk said during a tour with reporters.

Nissan, whose North American headquarters is in Franklin, Tenn., is discontinuing production of the Titan pickup and two sports utility vehicles in Canton to make way for the commercial vehicle. Bednarzyk said the Altima and other cars would continue to be built in Canton.

Like other automakers, Nissan has been hurt by declining sales, especially in the important U.S. market where a financial crisis and credit crunch have sent auto sales tumbling.

Bednarzyk said Nissan will expand the assembly shop and paint shops in Canton plus expansions in other areas. Renovations will include wider aisles, lengthened chassis carriages and a belt-loosening in the paint plant. At least one new building will be added.