According to Alfredo Altavilla, plants in France's Chambery, Austria's Graz and Germany's Weisweill, Goerlitz and Ulm will close.
But the Ulm site is set to be replaced by a centralised production centre.
The closures will affect 1,075 employees, said Altavilla, speaking at the launch of Iveco's new Stralis truck.
"These are painful closures but they will boost our overall business. We have not however cut our investment," he said. "When the markets recover we will be ready."
In May Iveco's subsidiary Camiva announced that it would close a plant in southeastern France. The 171 employees were expected to be deployed.
Fiat Industial, Italian auto giant Fiat's non-car business, posted a net profit of €207 million ($262 million) for the second quarter of 2012, up 93 percent from its profit for the first three months of the year of €114 million ($166 million).