The Turkey international will undergo a medical with Rennes on Wednesday after the two clubs concurred on an €8 million deal.
Erding, who joined PSG from Sochaux in 2009, has seen first-team opportunities very limited at the Parc des Princes in recent times, making just six starting appearances to date this season.
The 24-year-old striker turned down an €8.5m move to Newcastle in the summer after failing to agree personal terms with the Premier League side, despite both clubs reaching an agreement.
Rennes sit fifth in the Ligue 1 table, eight points adrift of leaders PSG, and host Olympique de Marseille in this weekend's match.
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