The skeletons were discovered along with Lebel rifles, the basic weapon of the French infantry during the Great War, in a forest near the town of Luneville, Philippe Sugg told AFP.
One of them had his identity tag and was a 27-year-old from an area near the southern city of Perpignan, he said.
Other items found included a pocket watch, a hip flask, two wallets and a little figurine of the Virgin Mary, he said.
Sugg, who is behind a two-man initiative to track down the remains of soldiers who died in the war which broke out a century ago, said they appeared to "have been killed in the exact spot they were found".
He said there was fighting in the area in September 1914.
The remains are likely to be interred in a nearby military cemetery apart from those of the identified soldier which may be laid to rest in a cemetery at his home town.