Mandanda, 32, starred for Marseille for nine seasons and helped them win the French title in 2010. He left for Palace a year ago but struggled in south London, making just 10 appearances.

Sources say OM paid up to five million euros (£4.5 million, $5.7 million) for Mandanda, who moved in the other direction last year for just two million euros.

Mandanda, who won the last of his 24 caps in September last year, is expected to reclaim the number one jersey at the Velodrome from Yohann Pele.

Meanwhile, the former European champions appear also set to clinch the signing of France centre-back Adil Rami from Sevilla.

Rami, who has won 33 caps and played for France at Euro 2016, indicated that he is on his way to the south of France by posting a picture of himself on Facebook with a Marseille logo on the wall in the background.

Rami, 31, played under current Marseille coach Rudi Garcia in the Lille side that won the league and cup double in 2011.

His signing would be the club's fourth of the close season, following earlier recruits of striker Valere Germain from champions Monaco and Brazil midfielder Luiz Gustavo from Wolfsburg.