Schwartz-Schilling, an official of the German Christian-Democratic Union (CDU) who used to be a minister in the government led by Helmut Kohl, was appointed by the Peace Implementation Council which held a session behind the closed doors in Paris on Wednesday morning.
The official announcement of his appointment as the successor to Briton Paddy Ashdown is expected in the course of the day.
Schwartz-Schilling will step in the office in January. Ashdown has been in this post for three and a half years.
After the 1994 Washington agreement was signed, laying foundations for the establishment of the Croat-Muslim federation in Bosnia, the German politician was an international mediator in the Federation and later for the entire Bosnia-Herzegovina.