Complex sentence: In the 1980s the Auckland and Wellington suburban rail networks were part of the government-owned New Zealand Railways Corporation, operating with Railways-owned buses under the brand name Cityline, renamed CityRail after the railway operations were transferred to New Zealand Rail Ltd in 1991.
Split into simpler sentences: In the 1980s the Auckland and Wellington suburban rail networks were part of the government-owned New Zealand Railways Corporation, operating with Railways-owned buses under the brand name Cityline. The rail operations were renamed CityRail after they were transferred to New Zealand Rail Ltd in 1991.