Council transport chairman cites lack of competition for the high outlays.
Auckland trains are costing almost as much as the region's buses to run, even though the buses carry almost five times as many passengers.
Council transport chairman Mike Lee is blaming a lack of competition, in which train operator Veolia had its management contract extended for more than two years in March without public notification.
Although the trains made a record of almost 11 million passenger trips in the year to June 30 - compared with 2.5 million when Britomart opened nine years ago - that cost ratepayers and the Government $105.7 million.
It was well up on $87 million for 9.9 million passengers the year before, after hefty increases in track access charges paid to KiwiRail and in Veolia's management fee.