In an interview on ABC radio this morning, Gunns chief executive Greg L'Estrange said the company was proposing to use only plantation timber in the mill and would change to a different bleaching process, which will reduce the amount of chlorine emissions.

Mr L'Estrange said Gunns had been holding discussions with a number of environmental groups, which he described as positive.

"We think by embedding some of those voluntary undertakings that we've given to date would be a very positive thing to be able to incorporate those in the permits so that everyone would be comfortable in going forward with the operation," he told the ABC.

A decision on the mill's final environmental approval was due last Thursday, however the company sought tougher controls, prompting Environment Minister Tony Burke to extend the announcement until Thursday this week.