The Federal Environment Department has revealed it has started talks with UNESCO to reduce Tasmania's newly-expanded World Heritage Area.

Under the forestry peace deal, 170,000 hectares were added to Tasmania's World Heritage Area earlier this year, including parts of the Styx, the Florentine and the Great Western Tiers.

The Federal Coalition insisted at the time it did not support the deal, or the new boundaries, and would seek to undo them if it won the election.

At a Senate Estimates session yesterday, the Federal Environment Department's Alex Rankin said there had already been talks with the World Heritage Committee about boundary changes.

"They were very informal so it was just trying to get some clarification around what processes are available within the operational guidelines of the World Heritage Committee for state parties to seek to change boundaries of listed places and what processes we may need to go through," she said.

"The only option for Australia would be to renominate with a reduced boundary."

She said in the past, the committee has agreed to change boundaries in areas where the heritage values had been destroyed or lost.

During the election campaign, the Coalition promised to remove World Heritage protection from areas including the Great Western Tiers forests.

After the September federal poll senior Liberal Eric Abetz said the new government would do all it could to "unpick" the forestry peace deal.

But industry peace deal signatory Terry Edwards warned the election result was not a mandate to tear up the agreement.