The 24-year-old, the leading scorer in Serie A last season with 22 goals, made his debut for Italy in their goalless draw with the Republic of Ireland in London on Saturday in a World Cup warm-up match.

"It is decided. I only have to put my signature on the contract. On Monday, I'm going to Germany," he told Italian broadcaster Rai Sport.

Representatives from Immobile's former club Juventus, who still part own the striker, and their city rivals Torino have met to discuss the details of the transfer, according to Italian sports daily Gazzetta dello Sport.

The two clubs will split the transfer fee evenly according to the Gazzetta.

Immobile is set to replace Dortmund's top-scorer, Poland striker Robert Lewandowski, who will join rivals Bayern Munich for next season.