L’Equipe reported on Saturday that talks were being concluded over a return to France for the 32-year-old goalkeeper.
Marseille hopes to conclude the transfer before the end of June for £2million, slightly more than Palace gave them last summer.
The France goalkeeper has not played since undergoing knee surgery in November .
The Eagles paid £1.5million for Mandanda last summer – and gave him a three-year contract worth £60,000 a week.
Mandanda spent nine seasons at Marseille and his family have stayed in the south of France this season.