The German government's security council in Berlin has signed a preliminary request for 40 fighter jets according to the source, who wants to remain anonymous since the information is confidential.
Turkey sent its request to make the deal over two years ago.
Eurofighter is a cooperation project between British BAE Systems, Italian Leonardo and with important components from German companies.
A spokesperson for the German government did not want to comment on the information, referring to the fact that matters in the security council are confidential.
The information that Germany has given the green light for the deal was first reported by the German newspaper Der Spiegel.
