Irish Continental Group, the operator of Irish Ferries, said its revenues rose by 1.4% to €96.4m in the first four months of the year.
A trading statement from the company reported an increase in its consumer and freight business during the period.
But ICG said it had taken a €2.5m revenue hit relating to the delay in the arrival of its new WB Yeats ferry.
The ferry had been due to start sailing on the Dublin-Cherbourg route on July 12, but the company making the vessel said its delivery would be delayed which resulted in ICG cancelling a number of sailings.
ICG said that total revenues in its Irish Ferries division dipped by 2.4% to €52.3m in the fourth month period, while total revenues in its Container and Terminal Division rose by 6.1% to €46.8m.
ICG noted that its business is "significantly" weighted towards the summer period when a higher proportion of the group's operating profit is normally generated.
It also said that fuel costs continue to be impacted by higher global fuel prices compared to the previous year.