The Bluebirds had been asked to make the first payment of 6million euros (£5.27m) to Nantes on February 20, but Press Association Sport understands the clubs have agreed a delay of one week.
Sala was killed when the private plane bringing him to Cardiff crashed into the English Channel on January 21, just two days after his record move to the Premier League club.
The 28-year-old body's was recovered from the crash site and his funeral – attended by both Cardiff and Nantes officials – took place in his native Argentina last Saturday. Lincolnshire pilot David Ibbotson remains missing, presumed dead.
In the weeks since Sala's disappearance, the two clubs have been at odds over what has threatened to escalate into a bitter dispute.
Nantes' lawyers wrote to Cardiff on February 5 asking for the first of three annual payments for the player, as was agreed last month, to be paid within 10 working days.
Cardiff, however, have made it clear they want to wait until the investigation into the crash is complete.
They are also querying "anomalies" in contract details, but club chairman Mehmet Dalman has said they will be "honourable" with Nantes over the transfer fee if they are contractually obliged to play.
Cardiff say several questions must be answered about the accident, most notably if Ibbotson was even qualified to be flying with a paying customer in that particular plane and the role of Monaco-based intermediary Willie McKay in the transfer and the flight.
Any wrongdoing in regards to the flight could annul the Welsh club's reported £16m insurance policy for Sala and, if that wrongdoing was another party's responsibility, they may have to sue for compensation.
On the other side, Nantes are equally understandably eager to find a replacement for Sala, their leading scorer for the last three seasons.
The situation is further complicated by Nantes owing Bordeaux 50 per cent of the fee because of a sell-on clause agreed when they bought Sala in 2015.
If the dispute is not resolved, it could end up in the hands of FIFA and its dispute resolution chamber (DRC), the body that arbitrates when players or clubs have a disagreement.
Its chairman is former Football Association chairman and FIFA vice-president Geoff Thompson.
However, it is possible that both sides would agree to skip a stage in the process and go straight to the Court of Arbitration for Sport in Lausanne.