Pre-tax losses at the operator of the Luas last year increased more than four fold to €2.75 million in spite of record numbers using the service.
Last year, the Luas in Dublin catered for a record 41.8 million passenger-journeys - an 11% increase over the previous year.
However, new accounts by French-owned Luas operator, Transdev Dublin Light Rail Ltd show that pre-tax losses at the company last year soared by 352% from €609,301 to €2.755m.
The losses came as revenues increased by 17% from €33m to €38.68m as Transdev benefited from the first full year operation of the Luas Cross City extension.
The directors attribute the increased losses to the bid costs for the new Luas Contract which the company secured and to increased staff costs in line with a Labour Court recommendation.
The 2016 Labour Court recommendation allowed for a salary increases of up to 18.3%.
A spokeswoman for Transdev also confirmed that the losses reflect the impact of the opening of Luas Cross City.
"The Green Line extension increased energy consumption. In addition to the increase in energy costs, employee numbers grew too," the spokeswoman said.
"Transdev recruited Luas drivers and revenue protection officers. These additional staff are paid under the new wage costs as agreed by the Labour Court in May 2016," she added.
The directors state that the increase in revenues is a result of full year operations of Luas Cross City, time table changes and one-off additional works.
Numbers employed at the transport company last year increased from 324 to 355 with staff costs increasing by 13% from €16.8m from €18.99m.
Transdev is to start the new six year Luas contract with a further five year option on Sunday, December 1.
Directors' pay last year increased from €265,287 to €496,465.
The directors state that earnings before interest, tax, depreciation and amortisaton was €2m last year compared to €172,017 in 2017.
Shareholders' deficit at the end of last year totalled €2.26m. The company's cash pile last year also increased from €320,694 to €3.55m.