under whom?
Krauss-Maffei.
Leopard 2
The Leopard 2 is a main battle tank developed by Krauss-Maffei in the 1970s for the West German Army. 
what is referred as leopard 2e? The Leopardo 2E or Leopard 2A6E is a variant of the German Leopard 2 main battle tank, tailored to the requirements of the Spanish army,. mention any one comparison of it with other tanks? The Leopard 2A4 and Leopard 2E sport a much more powerful gun than the AMX-30 and M60 tanks. do you know when was it constructed? December 2003. and who is responsible for its construction? Germany. the main german battle tank that you mentioned earlier, when was it built? 1970s.
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Leopard 2 [SEP] Introduction
The Leopard 2 is a main battle tank developed by Krauss-Maffei in the 1970s for the West German Army. The tank first entered service in 1979 and succeeded the earlier Leopard 1 as the main battle tank of the German Army. It is armed with a 120 mm smoothbore cannon, and is powered by a V-12 twin-turbo diesel engine. Various versions have served in the armed forces of Germany and 12 other European countries, as well as several non-European nations, including Canada, Chile, Indonesia, Singapore, and Turkey. The Leopard 2 was used in Kosovo with the German Army, and has seen action in Afghanistan with the Dutch, Danish and Canadian contributions to the International Security Assistance Force, as well as seeing action in Syria with the Turkish Armed Forces against ISIS and the YPG.