Legal proceedings have been lodged in the Federal court on behalf of workers made redundant in October 2013 from Centennial Coal's Lake Macquarie mines.
Union spokeswoman Catherine Bolger said it is an obscure and discriminatory clause that no other employer in the coal mining industry relies upon. It is an outdated clause in the award when the compulsory age of retirement was 60.
Ms Bolger said the court action has been launched to ensure older mineworkers get what they deserve. She said:
They're reducing people's payout by about two-thirds, which we say is totally heartless and very unfair. Particularly given Centennial have just announced a profit in Australia of $213 million gross profit.
In a statement, Centennial said it will be up to the court to decide on the merits of the action.
Read the ABC News report on this here.