Taoiseach Enda Kenny has welcomed the decision by EirGrid to put forward an alternative route for the Grid West line.
EirGrid has announced details of a possible underground route for the controversial project.
Proposals to run a 100km-long high voltage power line on pylons across north Mayo to Co Roscommon have met with strong opposition.
The project forms part of a national plan to enhance electricity supply.
The Grid West initiative is aimed at addressing an infrastructural deficit as well as catering for increased demand and helping to secure supply for the future.
However, opponents have cited health concerns as well as the environmental impact of pylons along the route.
Despite numerous calls from community groups for the cable to be placed underground, EirGrid repeatedly stated that this was not technically possible.
A special meeting of Mayo County Council was told last year that the only feasible solution was to run the line on pylons and that this was standard international best practice for such a development.
The Grid West project manager told the meeting that a 400 kilovolt high voltage line could not be accommodated underground, as it would have no flexibility, extendibility, reliability or security.
Last January, the Government set up an independent commission to investigate the possibility of putting high powered cables underground.
At the time, EirGrid undertook to analyse the underground option.
The result announced today is a "preferred route" - mostly running along the existing road network from north Mayo to Flagford in Co Roscommon.
Speaking in Castlebar Co Mayo today, Mr Kenny said the expansion of the grid and the was essential for infrastructural improvements throughout the country and the development of the economy.
He said the overground option had caused controversy in many parts of the country.
He said he looked forward to the consultations that would take place in the coming months as people learned more about the proposals.
EirGrid has said the cable would run between Crossmolina and Ballina, down the east side of Lough Conn, northeast of Foxford and north of Charlestown, Ballaghaderreen and Frenchpark to the Flagford substation area, southwest of Carrick-on-Shannon.
Both overground and underground options will then be reviewed by the Government appointed independent panel, before any further progression of the Grid West project.
Warning over cost of underground option
EirGrid's chief executive has told RTÉ's Morning Ireland that putting the cables underground could cost a "multiple" of having pylons overground.
Fintan Slye said the cost would ultimately end up on consumers' electricity bills.
He said the cost had not yet been fully assessed, compared to the €240m overground option.
However, he acknowledged that it could be up to two or three times the cost.
Mr Slye said that the company had worked with the relevant local county councils and the National Roads Authority to plot the underground network along regional and secondary road networks.
He said the underground route has tried to avoid major towns along the way to minimise any possible disruption.