The Doncaster-based company said that as anticipated, a number of matters remain to be concluded prior to the start of work at the mine.
Production is scheduled to commence towards the end of 2011.
The Glenmuckloch East mine is an extension to ATH’s existing operation at Glenmuckloch which will finish in the autumn of this year.
Alistair Black, chief executive of ATH Resources, said: “This planning approval provides continued employment for 90 people in the area and is an important contributor to the future of the ATH business and the local economy in this part of Dumfries and Galloway.”
ATH operates surface coal mines.