His position will be filled in the interim by Hinrich J. Woebcken,who was recently announced as the new Head of the North American Region and Chairman of Volkswagen Group of America.
Woebcken
Horn started working for VW in 1990 and became the CEO in January 2014.
His departure came as VW is plunged into its deepest-ever crisis by revelations that it installed emissions-cheating software into 11 million diesel engines worldwide.
Volkswagen is facing multiple investigations in the United States and other countries regarding the cheating, which affected some 600,000 vehicles in the United States and more than 11 million worldwide.
The company is facing potentially tens of billions of dollars in fines and owner compensation.
Horn.
German prosecutors looking into scandal said on Tuesday that the number of suspects under investigation had increased from six to 17, but that no former or current board members are involved.
AFP reported that Horn made headlines last September shortly after the VW emissions-cheating scandal broke, saying at a vehicle launch event that the company “totally screwed up” and acknowledging that it likely would suffer big financial penalties due to the scandal.
In announcing Horn's exit, Volkswagen Group of America said "he would be leaving to pursue other opportunities effective immediately."
