Complex sentence: The Ringhoffer factory, nationalized after World War II and producer of trams for the entire Eastern bloc, was moved to Zličín in the 1990s, now operated by Siemens.
Split into simpler sentences: The Ringhoffer factory, which was nationalized after World War II, produced trams for the entire Eastern bloc. It was moved to Zličín in the 1990s and is now operated by Siemens.