The Partenopei have formalised their interest in the 23-year-old but the Ligue 1 outfit are holding out for more money after dismissing an opening bid
Olympique de Marseille have turned down an offer in excess of €12 millon [£10m] from Napoli for defender Nicolas N'Koulou, president Vincent Labrune has revealed.
The Partenopei had been linked with a move for the 23-year-old since the back end of 2013 and have now returned with another bid for the Cameroon international.
However, the Ligue 1 club are reluctant to allow one of their most prized assets to depart the Stade Velodrome for the money on offer.
Speaking to RMC, Labrune said: "We had an offer from Napoli in mid-December, which was for more than €12m, and was not acted upon. There is little chance of him going."