Ms Keneally and Planning Minister Tony Kelly are to make an announcement when they visit the Arrowfield thoroughbred stud near Scone this morning.

The stud is owned by John Messara, who opposes the plan for an open-cut mine at South Bickham, close to the upper reaches of the Pages River, a Hunter tributary.

Mr Messara said last night he didn't know the details of Ms Keneally's announcement but hoped it would be positive for the horse industry. He has previously called for a strategic review of Hunter land uses so the region can sustain its diverse industries.

But because the Premier had chosen to make an announcement at the stud, members of the surrounding community who have agitated against the mine hoped it would be to reject the proposal outright.

Bickham Coal says on its website that the 36 million tonne mine could add as many as 386 jobs to the Hunter Region and pump $150 million into the area's economy.

But Mr Messara warned that continued expansion of the coalmining industry could cost the horse-breeding region its coveted place on the international stage.