DHL currently employs 1600 people in its Irish express delivery operation spread across four separate divisions.
However, last month the company revealed that it intended to make 320 of its 650 staff redundant by August.
The job losses are in the domestic delivery division, DHL Express, which has been scaled back significantly.
It is understood that 93% of staff balloted voted to accept the redundancy terms.
SIPTU Branch organiser Pat Ward said efforts were continuing to avert some of the job losses.
He said it was hoped that some jobs could be saved on a self-employment basis by way of a service-partner agreement.
