ASX-listed company Comet Ridge is starting to review an aerial survey of areas in Buller, Greymouth and Waikato where it is looking to mine coal seam gas.

Comet planned to extract the coal seam gas to sell to electricity companies, said managing director Tony McCaul.

The company had completed an aerial survey and analysis was about to begin.

If the company found coal seam gas in sufficient quantities it could be producing the gas within a year.

The project could employ 30 people and the company always used local contractors for drilling, transport and earthworks.