In a statement issued on Basque "homeland day," ETA said it had entered a phase in which it would take "decisions from among all its members for moving forward," the daily Gara reported.
"ETA will examine the path that has been travelled and will take future decisions with responsibility," the statement said.
On April 8th, ETA said it had completely and unilaterally disarmed.
It provided the French authorities with the locations of around three and a half tonnes of guns, explosives and other weapons.
In 2011, amid a string of arrests of top ETA operatives and public outrage over bloodshed, ETA announced it was abandoning its armed campaign.
ETA was founded in 1959 as a group to promote the Basque culture. The Basque region is a linguistically unique area divided by the French-Spanish border.
But during the 1960s, ETA mutated into an organisation that took to shootings, bombings and kidnappings in pursuit of an independent state.
It has been blamed for the deaths of 829 people. Thousands more have been injured.
Sunday's statement gave no indications about the parameters of the internal consultation.
ETA had recently been seeking to negotiate its dissolution in exchange for amnesties or improved prison conditions for roughly 350 of its members held in Spain and France, and for current members living under cover.
But Spain and France have taken a hard line, saying the group must unilaterally dissolve.