The Hunter Valley's thoroughbred breeding industry says it feels unwanted in the region after the NSW government renewed an exploration licence for a potential underground mine in the Upper Hunter.

In the same statement the government said there would be no open-cut mine at the Drayton South site, regardless of landowner.

An open-cut mine in the area had been in the pipeline for about six years but was rejected for a fourth time in February after which mining giant Anglo American sold the Drayton South project to Malabar Coal in May.

President of the Hunter Thoroughbred Breeders Association Cameron Collins said the impacts of underground mining had the potential to threaten the industry as much as open-cut mining.

"The message the NSW Government has sent to our industry, employees and investors is that Australia's premier thoroughbred breeding industry is not valued, not protected and not wanted in the Hunter Valley," Dr Collins said.

"Mining and thoroughbred breeding are incompatible land uses in close proximity."

When rejecting the open-cut mine in February, the independent Planning Assessment Commission cited a number of problems with the proposal, including concerns about the effects of coal dust, poor air quality and blast noise on nearby farms, and reputational damage.

The project was fiercely opposed by two international horse studs in the region - Irish-owned Coolmore and Dubai-owned Darley - which would have been less than one kilometre from the open-cut mine site.

Public submissions about the amendments are open until December 14.