Early last year Windalco cut its production of alumina and put its workers on a three-day work-week, citing contraction in international demand for aluminium, caused by the effects of the worldwide recession.
Windalco says there has been some improvement in the global economy but the alumina industry has only seen marginal movement.
It says with no immediate resumption of production in sight, it was in the best interests of the company to make the 762 positions redundant.
The employees have been demanding for months that their positions be made redundant since working three days a week was not feasible. The structure will be implemented on 1 April, 2010.
A small complement of workers will be required to undertake activities aimed at preserving its assets and meeting legal and community obligations.