Galeries Lafayette is thought to be the new owner of Marks & Spencer's French stores.
Union sources say M&S staff will be told the name of the buyer at a meeting this afternoon.
Meanwhile, Galeries Lafayette says it has called a staff information meeting at exactly the same time.
This has prompted speculation that the department store chain has snapped up all 18 of M&S's French stores.
In August M&S said it would prefer to sell its 18 stores in France to a single group which would re-employ all the staff.
Alain Juillet, the head of the company's French operations told Le Figaro: "The best solution would be that a single group commits itself to taking on the majority of the staff... keeping the work contracts unchanged."
He acknowledged that keeping on all the 1,700 workers "will not be easy" but said "it must be done."
M&S confirmed Galeries Lafayette was one of the candidates, but Mr Juillet said interest has also come from non-French firms, "who see in such an operation the chance to penetrate town centers in one go, while also taking advantage of an excellent staff."
He said the group should have "a final list of two or three buyers" by early October.