Auckland Transport says city rail services have resumed and were expected to be fully operational by 2pm.
Photo: RNZ / Laura Tupou
The signal system failed at 11.15am, stopping all trains on the network for an hour and a half.
Auckland Transport is apologising for the suspension of train services across the city and tweeted that although trains were now working passengers could expect some delays and cancellations.
Affected trains were moved to the nearest station so passengers could get off.