A new owner of the pulp mill permit would have until 2017 to start work on the $2.3 billion project, under legislation to be debated next week.
The proposed amendment, released a short time ago, puts the expiry date of the permit at 10 years from the passing of the original bill in April 2007.
Premier Lara Giddings announced last week that Parliament would be recalled later this month to approve the legislation which is designed to give potential buyers more certainty about the validity of the permit.
The legislation, which is set to be passed with the support of the Liberals, will quash a legal challenge from anti-pulp mill campaigners.
Gunns receivers say six international buyers are preparing bids for the failed timber company's assets, but not all are interested in the pulp mill.