The public consultation period for the North Connacht 110 kilovolt line is being extended by more than three weeks.
The new project will run from Ballina in Mayo to Ballaghaderreen in Roscommon.
Eirgrid say the aim is to facilitate the growth of renewable energy, and to upgrade the electricity infrastructure of the North West region.
The Eirgrid project team is currently evaluating possible routes for the line from a total of seven already identified in the study area.
Four of the routes would see an overhead line used, and underground cables would be used in the other three.
The consultation had been due to finish on this Monday the 16th but it's now extended until the 11th of December.