The 20-year-old only joined the club from Nordsjaelland in July 2016, signing a five-year deal at the German giants.
However, Mor only made 12 appearances under former boss Thomas Tuchel and current coach Peter Bosz is also willing to let him leave.
Liverpool and Everton are reportedly interested in his services but Inter Milan are winning the race for his signature.
Dortmund are happy for the Turkey international to leave this summer and they confirmed their intentions on Wednesday.
The club tweeted: "Emre Mor is missing from the shooting of the team photo.
"He has been freed for final talks on his future."