Alcoa workers fear the company is about to announce the closure of its Geelong aluminium plant, costing hundreds of jobs.

The union covering the 700 full-time workers at the Point Henry factory expect an announcement any day.

‘‘I’m very pessimistic about what that announcement will be,’’ said Ben Davis, state secretary of the Australian Workers Union.

He expected the company to confirm its departure from Geelong ‘‘in the next few weeks’’.

It follows Toyota’s announcement on Monday that it will close its Altona car-making factory in Altona in 2017, costing 2500 jobs.