The 27-year-old was allowed to leave Auxerre after they dropped to Ligue 2.
There was no mention of a fee in their statement, although they specified he had been offered a three-year contract after passing a medical.
Contour scored five goals in 35 appearances last season. He had previously played for Amiens, Metz and Beauvais.
Auxerre, meanwhile, have signed two Gabonese defenders as they prepare for life in the second tier.
Remy Ebanega, 22, and Henry Ndong, 19, both join from US Bitam in their homeland.
Both will join up following the Olympic Games in London, with Ebanega captaining his country’s team.