Mining contractor Macmahon Holdings expects to make just $2 million on the sale of its construction business to Leighton Holdings due to $12m in redundancy costs.

Macmahon announced earlier in December it would sell its construction activities to become a dedicated full service mining contractor.

After recent adjustments for new work and projects, Macmahon said its deal with Leighton would be worth $20m and produce proceeds of $14m after transferring employee liabilities to Leighton.

But Macmahon expects to incur $12m in restructure and redundancy costs associated with staff that will not be transferred to Leighton.