Up to 500 Christchurch aged care workers have lost their jobs in the wake of the region’s devastating earthquake.

Nurses, carers and support workers have been hit with redundancies at five aged care centres following the 6.3 magnitude quake that rocked the city on February 22.

New Zealand’s largest aged care business, Oceania Group, has revealed it will close two condemned sites at Woodchester in Shirley and Windermere in Papanui affecting 250 staff while three other aged care facilities have also been closed by the quake.

New Zealand Nurses Organisation coordinating organiser Lynley Mulrine, who lives and works in Christchurch, said the Oceania Group move was another knock for workers and residents in the embattled area.

"This is a huge blow to the sector and will result in a devastating loss of skills," she said.

"These ‘beds’ will have to be returned to the region through re-building and the skills (are) an important part of that."

Ms Mulrine said Oceania Group’s decision, which the organisation states will see some staff redeployed and others made redundant, was "extremely disappointing" given Canterbury District Health Board had guaranteed funding to employers who evacuated residents due to safety concerns.

"For workers to suffer the devastating effects of the quake and then lose their livelihood was a tremendous blow to them and their families and we now learn that this was avoidable," she said.

"It’s a heartless approach from a large employer whose livelihood comes from government funding."

Ms Mulrine said employees covered under the Collective Agreement and members of either NZNO or the Service and Food Workers Union were entitled to redundancy payments, however those who had worked for less than 12 months would miss out.

She said many of the workers at the other three aged care facilities had no entitlement to redundancy.