General Motors' Australian unit Holden said falling demand and the high Australian dollare had led it to cut about 170 jobs at its assembly plant in Adelaide through a voluntary separation programme.

The move would better align production with customer requirements and projected future volume and was a necessary step to ensure that the automaker was able to continue to have a viable manufacturing operation in Australia for the next decade, Holden said.

"Situations like this are always difficult and this decision has not been made lightly. The company will work together with employees and representatives to ensure that people are able to make informed decisions about their future," it added.

"Employees will have access to a number of support services during this transition.

"Every effort has been taken to avoid this decision, including the use of 'market response [non-production] days', however current new car demand necessitates a reduction to permanent employees.

In line with local union deals, workers have been offered voluntary separation and Holden anticipates the required reductions can be achieved through these alone.

"Holden Vehicle Operations has responded to changes in consumer demand many times over the years, and this latest adjustment is necessary in order to continue Holden's plan to sustain auto manufacturing in Australia for the long-term, and the implementation of GM's plan to build two new models in Australia through until 2022," the automaker added.

"Holden must continue to remain responsive and flexible to the ebbs and flows of the industry and our customers."

Holden had earlier threatened to end Australian car manufacturing by 2016 but a deal earlier this year with the government raised the axe until 2022.