The Loch Lomond and Trossachs National Park Planning Authority accepted the Scottish gold miner’s application to extend operations to March 2018.
The original permission ran for nine months and was due to finish in a few weeks' time at the end of February.
The additional time will allow Scotgold to fully explore the best ways to utilise the pilot plant and optimise the production process.
“We continue to learn more about the metallurgy and the economics of the project as we process our stockpile under the BPT,” said chief executive Richard Gray.
“This extension to the trial period not only affords us the opportunity to conclude our revisions to the economic assessment but it also throws off a small cash contribution to our costs from the resultant gold production.”
Scotgold will process 2,400 tonnes of stockpiled ore during the initial period and a further 4,800 tonnes over the course of the extension.
Shares were up 9% to 0.68p.