Icasa said in a statement that all Icasa employees at the management level and below were entitled to an inflation-related salary adjustment on July 1 of every year.
But over the past three years, the union and Icasa had not found common ground in their annual salary negotiations.
"The CWU and Icasa have, for the first time ... agreed to an 8.5% wage increase for Icasa employees on the ranks of manager and below," Icasa said.
Icasa's chief executive officer, Nkateko Nyoka welcomed this wage deal and said it marked a movement away from an adversarial approach to negotiations that had characterised the CWU and Icasa's relationship in the past.
A CWU spokesperson could not be reached for comment.