Bickham has issued the research in preparation for public hearings on the mine in Scone today and tomorrow.

The hearings, conducted by a planning panel appointed by the State Government, will look at Bickham's potential effect on the adjacent Pages River.

The new research, by the Hunter Valley Research Foundation, predicts Bickham would create work for another 286 people on top of the 100 people it would take to operate the mine.

Bickham director John Richards said this was substantially higher than the 200 extra jobs the NSW Department of Planning had estimated would go with the mine.

Mr Richards said the foundation had found the mine would add up to $150 million a year to the Hunter economy, or about $3.7 billion over the mine's expected 25-year life.

Royalties to the state could exceed $215 million.

The report said these figures were conservative.

The foundation said the Upper Hunter's population had fallen by nearly 8 per cent between 1996 and 2006. The number of 25- to 39-year-olds had fallen by 24 per cent.

Mr Richards said Bickham was determined to employ local people where possible, which would help ease the region's job shortage.

"We have always said we will employ local people where possible, and it's welcome news that we may be able to create many more local jobs than first anticipated," he said.