In 1900, the blast furnaces of Saint-Louis were the only ones in France still producing
ferromanganese. As the French steel mills became more and more located in Lorraine, a new
production site for ferromanganese was looked for in northern France. At the Channel coast,
the recently modernized blast furnaces of Outreau wanted to diversify their fabrications.
The two companies came to an agreement and the ferromanganese activity was transferred
to this site with great industrial and commercial success. In 1906, a blast furnace
moved from Marseille was started up at Outreau as a ferromanganese furnace.