ZiU

Trolza (Russian: ZАО "Троллейбусный завод" (Тролза)), formerly known as the Uritsky factory or simply Uritsky, is a former trolleybus manufacturer in Russia, located in Engels, Saratov oblast. In the Soviet era it was known as ZiU (Russian: Завод имени Урицкого, Zavod imeni Uritskogo, plant named after Moisei Uritskiy) or Uritsky factory.

ZiU/Trolza has built over 65,000 trolleybuses. Historically, the most numerous models of ZiU production were the MTB-82, the ZiU-5 and the ZiU-9 (also known as the ZiU-682). The ZiU-9 is the most widely produced trolleybus in history. The factory has exported its production to various countries, including Argentina, Bulgaria, Colombia, Greece, Mongolia, Hungary, Serbia etc.