Ouest France newspaper reports that the owner of the hotel in the coastal resort of Bénodet saw the online advertisement offering his hotel for €2 million ($2.5 million) in mid-May.
The ad was posted on the popular Le Bon Coin website. It was advertised as a "3-star hotel-restaurant, 51 rooms" offering "first-rate position by the sea."
While the hotel wasn't named, it didn't take locals long to realise it was the Hotel l'Abbatiale.
The owner told the newspaper he had indeed been looking at the possibility of selling the hotel in January as a way to deal with some financial issues.
He had even contacted a real estate agent and prepared an advertisement which ran in January, but was then withdrawn after he decided to keep the hotel.
It seems that an eager employee at the agent decided to renew the advertisement but forgot to tell the hotel owner.
"There's no reason to sell or find money to keep the hotel running," he said. "We have plenty of customers and the season's going well."